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  • 更新日期:2019-01-18
  • Electrospun PVDF/PSSLi ionomer films as a functional separator for lithium-sulfur batteries
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-18
    Yangsen Lin, Rosaiah Pitcheri, Jinghui Zhu, Caiming Jiao, Ya Guo, Jing Li, Yejun Qiu

    A novel polyvinylidene fluoride/poly(4-styrenesulfonic acid) lithium salt (PVDF/PSSLi) composite membrane has been successfully produced by a facile route. This membrane is proven to be effective for depressing polysulfide shuttle in lithium-sulfur battery, leading to higher discharge capacity and better durability in comparison with the commercial PP separator. The Li-S cell with PVDF/PSSLi separator delivers a discharge capacity of 1194 mAh/g with average Coulombic efficiency of 97% at 0.2 C. Especially, the PVDF/PSSLi membrane exhibits excellent cycling performance at 0.5 C, and the corresponding capacity decay is just 0.26% per cycle during 200 cycles, while that of PP separator is 0.43%; moreover, it possesses stable and high Coulombic efficiency of beyond 97% during cycling.

    更新日期:2019-01-18
  • Rate-dependent plastic deformation of TiZrHfCuNiBe high entropy bulk metallic glass
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-18
    Y. Tong, J.C. Qiao, J.M. Pelletier, Y. Yao

    Rate-dependent plastic deformation behavior of TiZrHfCuNiBe high entropy bulk metallic glass (HE-BMG) is investigated by the nanoindentation and quasi-static compression tests. The experimental results reveal that the pop-in sizes during nanoindentation and the serrations sizes under compression will reduce when the loading/strain increases. The strain rate sensitivity during nanoindentation creep is enhanced as loading rate increases, which represents more homogeneously deformation of TiZrHfCuNiBe HE-BMG at higher loading/strain rate. The average serrations sizes of TiZrHfCuNiBe HE-BMG are significantly smaller than that of traditional bulk metallic glasses. The plastic deformation behavior of the TiZrHfCuNiBe HE-BMG is discussed with resepect to the self-organized critical (SOC) state behavior. The results demonstrated that the shear-band interactions of multiple shear bands could affect the SOC behavior and inhomogeneous deformation. Research suggests the shear transformation zone (STZ) sizes become smaller as the loading rate increases based on the statistical analysis. It is ascribed to have a larger shear band density at lower loading/strain rate. The current research is in coincidence with the shear-band patterns shown in microscopic micrographs of specimen surfaces. More shear-banding distributions at the lower loading/strain rate will result in more inhomogeneous deformation.

    更新日期:2019-01-18
  • Bi-based semiconductors composites of BiVO4 quantum dots decorated Bi12TiO20 via in-suit growth with ultrasound for enhancing photocatalytic performance
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-18
    Tao Wang, Xiqing Liu, Donglai Han, Changchang Ma, Yang Liu, Pengwei Huo, Yongsheng Yan

    In this work, two Bi-based semiconductors composites was synthesized through the BiVO4 quantum dots (BVO QDs) was grown on the Bi12TiO20 (BTO) via an in-suit growth with the ultrasonic method, which was more stability and evenly dispersed. As expected, the BVO-BTO composites exhibited increased visible-light-driven photocatalytic performance for photo-degradation due to the advantages of BVO QDs. Moreover, the possible mechanism of BVO-BTO composites was studied by trapping experiment, photocurrent, UV–vis and so on. The results demonstrated that the BVO QDs can widen the light response range to visible region and hasten the charge transfer and separation. Thus, the photocatalytic activity was enhanced through the BVO QDs decorated on BTO, which provided a new idea for designing Bi-based materials.

    更新日期:2019-01-18
  • Investigations of Ce-Zn co-substitution on crystal structure and ferrimagnetic properties of M-type strontium hexaferrites Sr1-xCexFe12-xZnxO19 compounds
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Chaocheng Liu, Xucai Kan, Feng Hu, Xiansong Liu, Shuangjiu Feng, Jiyu Hu, Wei Wang, Khalid Mehmood Ur Rehman, Mudssir Shezad, Cong Zhang, Haohao Li, Shengqiang Zhou, Qiuyue Wu

    Herein, we have systematically illustrated the specific impact of Ce-Zn co-substituted M-type strontium hexaferrites on its microstructure and magnetic properties. An evident phase pattern change process and performance improvement are observed from a series of systematic measurements. The results of X-ray diffraction show that the single phase can be obtained when x = 0.00–0.30, the other unexpected diffraction peaks of hematite (α-Fe2O3) will appear in the patterns as x > 0.3. Scanning electron microscopy exhibits that all samples formed the uniform plane hexagonal structures with different substitution contents. FT-IR spectra verify the confirmation that M-type hexagonal structure has been formed thoroughly. M(T) curve displays the ferrimagnetic behavior of temperature dependent magnetization. And vibrating sample magnetometer indicates both Ms and Hc can be improved significantly, indicating an excellent performance in novel recording devices.

    更新日期:2019-01-18
  • Sintering behavior, microwave dielectric properties of Ca0.66Ti0.66Nd0.34Al0.34O3 ceramics revealed by microstructure and Raman scattering
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Yue Xu, Renli Fu, Ping Zhao, Xibin Yi

    Ca0.66Ti0.66Nd0.34Al0.34O3(CTNA) ceramics were prepared by solid-state reaction method and their sintering behavior, microwave dielectric properties, and microstructure were investigated. CTNA ceramics were examined by Raman scattering to reveal the correlation of perovskite structure with the microwave properties. It found that the area of peak A1g(O) stretch mode reflects the quality factor Q × f value in the perovskite materials. This concludes that the oxygen octahedron plays an important role of the material's microwave performance. Sintering temperature affected the unit cell volume and the lattice parameters of the CTNA ceramics, the grain size distribution, the Gibbs free energy, the thermal expansion coefficient (CTE), and the dielectric properties (εr, Q×f, τf). The samples sintered at 1500 °C displayed the best dielectric constant and Q×f, as 44.94 and 41922.22 GHz, respectively.

    更新日期:2019-01-18
  • Achieving Janus Ag@N-doped carbon for oxygen reduction reaction from eccentric encapsulated Ag@polypyrrole
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Liang Zhang, Xinyue Wang, Tingting Zhang, Chengzhan Liu, Dehua Li, Shuangxi Xing
    更新日期:2019-01-18
  • A comparative study of glass-forming ability, crystallization kinetics and mechanical properties of Zr55Co25Al20 and Zr52Co25Al23 bulk metallic glasses
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Q. Dong, Y.J. Pan, J. Tan, X.M. Qin, C.J. Li, P. Gao, Z.X. Feng, M. Calin, J. Eckert
    更新日期:2019-01-18
  • Effect of ultrasonic vibration on the intermetallic compound layer formation in Al/Cu friction stir weld joints
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Najib A. Muhammad, C.S. Wu, Weihong Tian

    Dissimilar aluminium alloy and pure copper joints were produced using a novel ultrasonic vibration assisted friction stir welding (UVaFSW) assembly. The intermetallic compounds (IMCs) formed at the Al-Cu interfaces were characterized using a scanning electron microscope and energy-dispersive X-ray spectroscopy analysis. The thermodynamic prediction of the first intermetallic compound formation using effective Gibbs free energy change of formation (EGFEF) model was used to calculate the first intermetallic compound layer to nucleate or form during each process condition at the joint interface. The results show that irrespective of the welding conditions (with and without ultrasonic vibrations) intermetallic compounds are formed at the interface. However, the ultrasonic vibration effectively reduced the thickness of the IMC layer at the joint interface and consequently improved the mechanical properties of the joints.

    更新日期:2019-01-18
  • Magnetization reversal of hard/soft magnetic bilayer
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    T.A. Taaev, K.Sh. Khizriev, A.K. Murtazaev

    We present a model of hard/soft magnetic bilayer for the Monte Carlo investigation under the external magnetic field. The influence of the exchange interaction constants of soft magnetic layer Jsoft on the magnetic bilayer magnetization reversal processes is explored for the first time. Behavior of the magnetic bilayer under the external magnetic field is shown to agree with theoretical predictions well enough.

    更新日期:2019-01-18
  • Nitrogen doped Co-Cr-Mo-W based alloys fabricated by selective laser melting with enhanced strength and good ductility
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Bo Wang, Xinglong An, Zonglian Huang, Min Song, Song Ni, Shaojun Liu
    更新日期:2019-01-18
  • Simultaneously enhanced far-red luminescence and thermal stability in Ca3Al4ZnO10:Mn4+ phosphor via Mg2+ doping for plant growth lighting
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Liangling Sun, Balaji Devakumar, Jia Liang, Shaoying Wang, Qi Sun, Xiaoyong Huang
    更新日期:2019-01-18
  • 更新日期:2019-01-18
  • Reactive spark plasma sintering and thermoelectric properties of Nd-substituted BiCuSeO oxyselenides
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Andrei Novitskii, Gabin Guélou, Dmitriy Moskovskikh, Andrei Voronin, Elena Zakharova, Larisa Shvanskaya, Aleksei Bogach, Alexander Vasiliev, Vladimir Khovaylo, Takao Mori

    Bi1-xNdxCuSeO (x = 0; 0.05; 0.10; 0.15) was fabricated by the solid-state reaction and the reactive spark plasma sintering for comparative study. It was demonstrated that BiCuSeO could be formed in-situ by the reaction between Bi2O3, Bi, Cu and Se during the densification process. The effect of Nd doping on the thermoelectric properties has been investigated. The results indicated that for both series of the samples the substitution of Bi3+ by Nd3+ resulted in the increase of charge carrier concentration mainly caused by Bi/Cu deficiencies formation with the substitution. However, the specimens obtained by reactive spark plasma sintering had lower hole concentration which may originate from the high speed of the process resulted in induced point defect and interface scattering and another phase formation mechanism leading to the smaller amount of Bi/Cu deficiencies.

    更新日期:2019-01-18
  • Impact on photon-assisted charge carrier transport by engineering electrodes of GaN based UV photodetectors
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Neha Aggarwal, Shibin Krishna, Shubhendra Kumar Jain, Arzoo Arora, Lalit Goswami, Alka Sharma, Sudhir Husale, Abhiram Gundimeda, Govind Gupta

    A scheme illustrating electrode-engineering in metal-semiconductor-metal geometry is employed for fabricating GaN based high-performance ultraviolet photodetectors. The effect of different metal-semiconductor (Au, Ti/Al and Al) junctions on photon-assisted charge-carrier transport and the current-conduction is explored. Depending upon work function of the metals, barrier height varies which contributed towards different characteristics of the device revealing linear and non-linear behaviour of the electrical measurements from the non-rectifying and rectifying contact at the metal-semiconductor interface respectively. A maximum photoresponsivity & efficiency of 280.4 mA/W and 107.04% under 5 V applied bias in visible-blind region was measured from the device with rectifying Au electrodes while the photoresponsivity values of 219 mA/W and 200 mA/W under the same bias has been achieved from devices measured with near-Ohmic contacts using Ti/Al and Al electrodes, respectively. The enhancement in detector's performance with Au electrode has been attributed to the built-in electric field as well as the presence of internal gain which can promote efficient transport of charge carriers through the metal-semiconductor interface. Thus, an approach has been adopted to enhance the photoresponsivity of the fabricated GaN based opto-electronic devices which could be utilized for wide range of industrial, military, environmental and biological applications.

    更新日期:2019-01-18
  • Cold sprayed WC reinforced maraging steel 300 composites: Microstructure characterization and mechanical properties
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Chaoyue Chen, Yingchun Xie, Xincheng Yan, Renzhong Huang, Min Kuang, Wenyou Ma, Ruixin Zhao, Jiang Wang, Min Liu, Zhongming Ren, Hanlin Liao

    Maraging steel 300 (MS300) is a precipitation-strengthening iron–nickel alloy with outstanding properties such as good mechanical strength, weldability and corrosion resistance. However, the poor wear resistance has limited the application. In this work, high-performance WC reinforced MS300 composites were fabricated by high-pressure cold spray, which enables the additive manufacturing of bulk material well below its melting point. XRD analysis shows that no phase transformation occurred either to the WC reinforcements or the MS300 matrix. The distribution and morphology of the WC particles in the composite samples were characterized by X-ray computed tomography (XCT). The results show that a high retainability (85.4%) of WC particles was obtained at high working parameters (N2, 5 MPa, 900 °C), and the solution-aging treatment resulted in decreased WC volume fraction and smoothing of WC shape. Microstructure observation of WC evolution shows that a thick diffusion layer was formed around the WC particle after solution-aging treatment significantly improving the interfacial bonding. Due to the more severe plastic deformation and higher WC retainability, the as-fabricated samples with higher propelling gas pressure demonstrate a higher tensile strength and better wear resistance. It is found that a higher solution temperature (1000 °C) can lead to an enhanced cohesive bonding within the composite. Finally, the solution-aged composite shows an excellent wear resistance under the improved WC bonding and precipitation hardening.

    更新日期:2019-01-18
  • Fabrication and characterization of dinickel orthosilicate nanosheets as high performance anode material for lithium-ion batteries
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Shuzhen Yang, Yanfang Huang, Duo Zhang, Guihong Han, Yijun Cao, Jiongtian Liu

    Metal silicates are a class of high capacity anode materials for rechargeable lithium-ion batteries (LIBs). Nickel silicate (Ni2SiO4, NSO) was successfully synthesized through the process of chemical precipitation-calcination-alkali washing as a potential anode for LIBs in this work. The characterizations of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and Brunauer Emmett Teller (BET) were conducted to examine the surface and structural properties of the NSO. The results indicate the products are pure Ni2SiO4 and in petal-like nanosheet morphology with a specific surface area of 30.29 m2 g−1. A high reversible capacity of 874.7 mAh g−1 is obtained after 50 cycles at a current density of 0.1 A g−1, with 81.8% of the capacity being maintained. In addition, the NSO nanosheets hold a superior reversible capacity of 473.9 mAh g−1 at a current density of 1.6 A g−1. Furthermore, cyclic voltammetry tests and electrochemical impedance spectra were applied to investigate the electrochemical process in the battery. The NSO nanosheets display good cycling stability and excellent rate capacity. The obtained results show that dinickel orthosilicate nanosheets can be considered as a promising anode candidate for LIBs.

    更新日期:2019-01-18
  • Dispersion characteristics, interfacial bonding and nanostructural evolution of MWCNT in Ti6Al4V powders prepared by shift speed ball milling technique
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Avwerosuoghene Moses Okoro, Ronald Machaka, Senzeni Sipho Lephuthing, Mary Aimegho Awotunde, Samuel Ranti Oke, Oluwasegun Eso Falodun, Peter Apata Olubambi
    更新日期:2019-01-18
  • Influence of controlled Pd nanoparticles decorated TiO2 nanowire arrays for efficient photoelectrochemical water splitting
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Jingjing He, Meng Wang, Xiaofeng Wu, Yu Sun, Keke Huang, Huanwen Chen, Lu Gao, Shouhua Feng
    更新日期:2019-01-18
  • Hydrothermal crystal growth of 2-D and 3-D barium rare earth germanates: BaREGeO4(OH) and BaRE10(GeO4)4O8 (RE = Ho, Er)
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Kyle Fulle, Liurukara D. Sanjeewa, Colin D. McMillen, Channa R. De Silva, Katarina Ruehl, Yimei Wen, George Chumanov, Joseph W. Kolis
    更新日期:2019-01-18
  • Dislocation structures of B2 phase in Ti-42Al-6V-1Cr alloy deformed at room temperature and 800 °C
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Hongwu Liu, Zhenxi Li, Fan Gao, Qingfeng Wang

    The dislocation structures of B2 phase in Ti-42Al-6V-1Cr alloy deformed at room temperature (RT), 700 °C and 800 °C were investigated in detail. At RT and 700 °C, the 〈110〉 type dislocations were active in B2 grains. The {111}〈110〉 slip systems satisfy the von Mises criterion and this is a contributor to the ductility. At 800 °C, three different types of dislocations were observed, containing 〈111>, <110〉 and 〈100〉-type dislocations. Based on microstructural evidence, recovery process occurs by a combination of rearrangement of dislocations and subgrain structures. The more slip modes are activated and this would lead to softening.

    更新日期:2019-01-17
  • Thermal conductivity of giant magnetocaloric Mn compounds
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Hirofumi Wada, Kosuke Fukuda, Takayuki Ohnishi, Kei Soejima, Kensuke Otsubo, Keiichiro Yamashita

    Temperature dependence of the thermal conductivity of Mn1.03As0.70Sb0.30 and Ru-doped or Ni-doped (MnFeRu)2(PSi) was studied. These compounds undergo a first-order magnetic transition (FOMT) near room temperature and exhibit a giant magnetocaloric effect at around the Curie temperature. The thermal conductivity of Ru-doped and Ni-doped compounds is abruptly reduced at the Curie temperature during the first cooling. This is due to the micro-cracks generated during the FOMT. On heating, the thermal conductivity shows positive temperature dependence. The Ru-doped and Ni-doped compounds show small humps in the temperature dependence of the thermal conductivity near TC. The thermal conductivity of ferromagnetic metals is given by the sum of the phonon component, the electronic component, and the magnetic component. The results are discussed by taking account of the temperature dependence of each component.

    更新日期:2019-01-17
  • Highly efficient and thermal stable La2Si2O7:Ce3+,Tb3+,Eu3+ phosphors: Emission color tuning through terbium bridge
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-17
    Wentao Ma, Jilin Zhang, Xujian Zhang, Xinguo Zhang, Yongfu Liu, Shuzhen Liao, Shixun Lian
    更新日期:2019-01-17
  • Spatially limited antiferromagnetic order in a cluster glass compound Tb2Ni0.90Si2.94
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-16
    Santanu Pakhira, Chandan Mazumdar, Maxim Avdeev, R.N. Bhowmik, R. Ranganathan

    In the present study, the synthesis of a new ternary intermetallic compound Tb2Ni0.90Si2.94 has been reported. The detailed studies on structure, static and dynamical magnetic properties of the compound have been investigated by means of powder x-ray diffraction, compositional analysis, dc & ac magnetization, non-equilibrium dynamics, heat capacity and neutron diffraction measurements. The dc & ac magnetic susceptibility reveal that the compound undergoes spin cluster-glass behaviour below 9.9 K. The frequency dependence of the freezing temperature have been analyzed on the basis of dynamic scaling laws such as power-law divergence and Vogel-Fulcher law, which further confirm the cluster-glass state formation for the compound. A detailed study on non-equilibrium dynamical behaviour associated with cluster-glass state has been carried out through magnetic relaxation behaviour along with magnetic memory effect in zero-field-cooled (ZFC) as well as field-cooled (FC) conditions and associated aging effect. The zero-field neutron diffraction study reveals the presence of a spatially limited antiferromagnetic phase in addition to the magnetically frustrated cluster-glass state. This result has also been supported through zero-field heat capacity studies. The variation in local electronic environment among the magnetic rare-earth ions caused by the structural disorder associated with Ni/Si ions have been argued to be responsible for the coexistence of different magnetic phases.

    更新日期:2019-01-17
  • A study on the micro-evolution of mechanical property and microstructures in (Cu-30Fe)-2X alloys with the addition of minor alloying elements
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-16
    Yeon Beom Jeong, Hee Ra Jo, Jeong Tae Kim, Sung Hwan Hong, Ki Buem Kim

    The morphology of the phase and the grain size generally have a significant influence on the mechanical properties of the alloy. (Cu-30Fe)-2X alloys also significantly have been affected by the morphology and solidification process of the phase. Compared with the Cu-30Fe alloy, which has a dendritic Fe phase due to the separation of meta-stable liquid phases, the addition of Si causes the formation of a spherical Fe primary phase with a fine size, and enhancement of the volume fraction of the secondary separated Cu phase in the formed Fe phase and primary α-Fe phase. Moreover, it leads to an implement of yield strength that is about 35% greater than a Cu-30Fe alloy. The addition of Nb and V resulted in the formation of coarse Fe units, which resulted in a decrease in the yield strength due to the concentration of stress. These results will be used as useful data for industrial applications aimed at controlling microstructures and improving mechanical properties in alloy designs.

    更新日期:2019-01-17
  • Electronic bandgap manipulation of monolayer WS2 by vertically coupled insulated Mg(OH)2 layers
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-16
    Fang Wang, Anyang Cui, Huimin Sun, Bin Zhou, Liping Xu, Kai Jiang, Liyan Shang, Zhigao Hu, Junhao Chu
    更新日期:2019-01-17
  • Microstructure and properties of TiN/Fe-based amorphous composite coatings fabricated by reactive plasma spraying
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-16
    Zhenhua Chu, Fushuang Wei, Xingwei Zheng, Chunyue Zhang, Yong Yang

    In the present study, TiN/Fe-based amorphous composite coatings with various proportions were fabricated by reactive plasma spraying successfully. The Fe-based amorphous coated with TiH2 powders were prepared as feedstock. TiN as reinforcement phases was formed during reactive plasma spraying. The properties investigation indicate that the introduction of TiN does not affect the amorphous forming ability of Fe-based amorphous. And the corrosion resistance and abrasive property are improved due to the introduction of TiN in the composite coatings. The results show that the 15% TiN/Fe-based amorphous composite coating has the most stable performance and is also superior wear-resistant and corrosion resistant.

    更新日期:2019-01-17
  • The effect of the porosity on the Al2O3-YAG:Ce phosphor ceramic: Microstructure, luminescent efficiency, and luminous stability in laser-driven lighting
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-16
    Zehua Liu, Shuxing Li, Yihua Huang, Lujie Wang, Hui Zhang, Rongrong Jiang, Fan Huang, Xiumin Yao, Xuejian Liu, Zhengren Huang

    Solid-state laser lighting (SSL) fabricated by integrating laser diode with phosphor is a new development to achieve high luminance. Because of the high temperature caused by the laser, the phosphor-conversion apparatus is demanded to possess excellent thermal properties. In this paper, we utilized spark plasma sintering (SPS) to prepare the Al2O3-YAG:Ce phosphor ceramics with outstanding performances. Due to the high thermal conductivity and high transmittance, a high saturation input power (32 W/mm2) can be achieved for the sample with the lowest porosity. The correlated color temperature (CCT) and color rendering index (CRI) of composite ceramics with the lowest porosity are stable as the input power increases from 0.7 W/mm2 to 30.8 W/mm2. Nevertheless, the sample with the highest porosity shows the highest luminescence efficiency (305 lm/W) and luminous emittances (1796 lm/mm2), which can be ascribed to the scattering of the pore.

    更新日期:2019-01-17
  • High magnetic-dielectric tunability in Ni nanocrystals embedded BaTiO3 films
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-16
    Zhengwei Xiong, Linhong Cao

    A large lattice mismatch (>10%) system was designed, consisting of epitaxial BaTiO3 matrix and Ni nanocrystals (NCs). The interfacial stress was fully released by the formation of three-dimensional islands Ni NCs with a preferred (111) orientation. We further demonstrated that the elastic energy of (111) was much smaller than the (100) planes. The remarkable dielectric tunability of 0.41 at 100 Oe was obtained, attributing to the large magnetoelastic energy ΔH = 0.096 eV. Due to the smaller magnetoelastic energy density (2.32 × 106 J/m3) relative to the magnetocrystalline anisotropy energy densities, magnetically polarized Ni NCs could overcome the anisotropy field and diamagnetism of the BaTiO3 matrix, resulting in the easily tunable dielectric properties with a weak magnetic field. These discoveries represent great potential for magnetoelectric devices.

    更新日期:2019-01-17
  • In vitro degradation behavior and cytocompatibility of ZK30/bioactive glass composites fabricated by selective laser melting for biomedical applications
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-15
    Yong Yin, Qianli Huang, Luxin Liang, Xiaobo Hu, Tang Liu, Yuanzhi Weng, Teng Long, Yong Liu, Qingxiang Li, Shaoqiang Zhou, Hong Wu

    In practice, the poor formability and high degradation rate of Mg-based alloys are perceived as two major limitations for their more extensive applications in the biomedical field. Selective laser melting (SLM), as one of the advanced additive manufacturing techniques, is potential for the manufacturing of customized Mg-based implants with improved formability and corrosion resistance. Moreover, the integration of bioactive glass (BG) into Mg-based alloys could endow the materials with further enhanced corrosion resistance and favorable biological performance. In the current work, biomedical Mg-based biodegradable composites (ZK30/xBG, x = 0, 5, 10, 15 wt.%) with ZK30 alloy as the matrix and BG (45S5) as the reinforcement were fabricated by SLM. The results showed that the BG particles homogeneously distributed in the matrices of SLM-fabricated ZK30/xBG composites. Meanwhile, the introduction of the BG particles led to improved microhardness of the composites. When immersed in simulated body fluid (SBF), more precipitations (primary Ca–P compounds and partial Mg(OH)2) formed on ZK30/10BG and ZK30/15BG surfaces compared to ZK30 and ZK30/5BG group. The hydrogen evolution and electrochemical polarization tests showed that corrosion resistance of various specimens was in the following order: ZK30/10BG > ZK30/5BG > ZK30/15BG > ZK30. In addition, the in vitro cell viability results showed that ZK30/10BG and ZK30/15BG were more cytocompatible than ZK30 and ZK30/5BG. Overall, these results indicate that the combination of SLM technique and BG integration could be used to manufacture ZK30/xBG composites with enhanced corrosion resistance and favorable formability. Moreover, the ZK30/10BG composite is promising for orthopedic applications considering its combination of favorable bioactivity, corrosion resistance and cytocompatibility.

    更新日期:2019-01-15
  • Effect of equal channel angular pressing (ECAP) on the evolution of texture, microstructure and mechanical properties in the Al-Cu-Li alloy AA2195
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-15
    M. Suresh, A. Sharma, A.M. More, R. Kalsar, A. Bisht, N. Nayan, S. Suwas

    In this study, one of the severe plastic deformation (SPD) techniques, Equal Channel Angular Pressing (ECAP) has been successfully applied to the Al-Cu-Li alloy AA2195 at 250 °C and the development of microstructure, texture and mechanical properties has been studied. A systematic analysis has been carried out by using EBSD and TEM to understand the microstructural features, and the nature of different precipitates presence in the alloy AA2195. Microstructural features indicate considerable grain refinement leading to an average grain size of 2.8 ± 0.7 μm after 4 ECAP passes. Continuous dynamic recrystallization (CDRX) has been identified as the mechanism that leads to the formation of fine grain structure in the alloy AA2195 during the warm ECAP process. TEM results confirm the distribution of strengthening precipitates δ′(Al3Li), β(Al3Zr) and T1(Al2CuLi) in the alloy. The overall texture has become weak after ECAP processing and has been simulated using Visco-plastic self-consistent simulation (VPSC). The evaluation of mechanical properties indicates a substantial increment in hardness, strength properties with a minor reduction of ductility after 4 passes. Low mechanical property anisotropy is expected in the processed AA2195 alloy due to its weak texture.

    更新日期:2019-01-15
  • Pulsed constant voltage electrophoretic deposition of YSZ electrolyte coating on conducting porous Ni–YSZ cermet for SOFCs applications
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-15
    Omid Ekhlasi Oskouyi, Mohammad Shahmiri, Amir Maghsoudipour, Masood Hasheminiasari

    In the present investigation, solid oxide fuel cells (SOFCs) electrolyte coatings of 8 mol% Y2O3 stabilized ZrO2 (YSZ) are applied on Ni-YSZ cermet fuel cell anode in ethanol by pulsed constant voltage-electrophoretic deposition (EPD). Press pressure and sintering temperature as two of the most effective parameters for NiO-YSZ composite fabrication are investigated. In order to create electrically conductive anodes, NiO-YSZ composite is reduced in H2 atmosphere while its crystallinity being studied by X-ray diffraction (XRD). Pulsed constant voltage EPD process parameters such as pulse width, applied voltage and total deposition time are examined. The YSZ electrolyte film is sintered for 4 h at two different temperatures of 1300 and 1350 C°. Optical microscope (OM) is used to study the surface quality of coating. Substrate morphology and the quality of YSZ electrolyte film are investigated by scanning electron microscope (SEM). Atomic force microscopy (AFM) is used to probe the surface roughness and the morphology of green and sintered coatings. Results show improved deposition yield by increasing applied voltage and total deposition time. Uniform and dense coating was deposited at voltage of 35 V, pulse width of 1 ms, 50% duty cycle and total deposition time of 6 min having the thickness and roughness of about 17 ± 1 μm and 166 ± 5 nm, respectively.

    更新日期:2019-01-15
  • Structure-transmittance relationship in transparent ceramics
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    H. Shahbazi, M. Tataei, M.H. Enayati, A. Shafeiey, M. Azizi. Malekabadi

    Transparent ceramics are a kind of optical materials which have a wide range of applications in various engineering sectors, including the medical devices (implants, anti-wear coatings), cars, smartphones (anti-wear and shockproof plates), watches (anti-wear and anti-shock lenses with high strength), optical lenses, etc. Control of various parameters like the volume fraction of secondary phase, the grain size of the main and secondary phase, and the number of pores in unit volume, which affect the absorption, reflection and finally the transparency of ceramics, is a vital issue. Studying the physical aspects besides applying the principles of simulation is a very efficient way to achieve this aim. Simulation of the behavior of ceramics helps to attain optimized parameters. Therefore, to accomplish an optical ceramic with prominent transparency and admissible transmittance in selective wavelengths, the appropriate simulation theory should be used. In this paper, first, the physical basis of optical ceramics including band gaps, absorption, reflection, diffraction, refractive index, refraction, dispersion, etc., are briefly presented. Additionally, different simulation theories are reviewed and discussed.

    更新日期:2019-01-15
  • Roles of alloying elements in wetting of SiC by Al
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Qin An, Xiao-shuang Cong, Ping Shen, Qi-chuan Jiang

    Wetting of SiC by Al alloys is a key issue in the preparation of SiC-reinforced Al matrix composites. The wettability could be improved by alloying of Al, yet controversial results widely exist in the literature. We investigated the effects of four important alloying elements (Si, Cu, Ti and Mg) and their concentrations on the wettability in the Al/SiC system using a dispensed sessile-drop method. The results demonstrate that Si could weaken or even inhibit the formation of Al4C3 and substantially improve the wettability via an adsorption effect; Cu slightly deteriorates the wettability, but alleviates the formation of Al4C3 by decreasing the activity of Al; Ti strongly adsorbs at the solid−liquid interface, forming TiCx instead of Al4C3, and thus significantly improves the wettability; Mg may also favor the wettability due to its help in the disruption of the oxide film covering the Al surface via evaporation and its strong affinity for the silica film on the SiC surface; but for a clean Al/SiC system, the effect of Mg is essentially limited. In addition, the evaporation of Mg always leads to a reduction in the drop volume, which causes a decrease in the apparent contact angle, but this effect is usually neglected.

    更新日期:2019-01-15
  • Reformation of the surface of powdered activated carbon (PAC) using covalent organic polymers (COPs) and synthesis of a Prussian blue impregnated adsorbent for the decontamination of radioactive cesium
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Boksung Kim, Daemin Oh, Sungwon Kang, Youngsug Kim, Sol Kim, Yoonsuhn Chung, Youngkyo Seo, Yuhoon Hwang

    Prussian blue (PB) is known to selectively adsorb cesium (Cs), with a high adsorption efficiency. However, it is difficult to collect it after adsorption, which increases the risk of secondary environmental pollution. In this study, covalent organic polymers (COPs) were used to reform the surface of powdered activated carbon (PAC) particles in order to stably immobilize PB, with the aim of developing an adsorbent impregnated with PB (COP-PAC-PB). PAC particles reformed with COPs (COP-PAC) were analyzed using TEM (EDS) and FT-IR techniques, and it was found that COPs were successfully synthesized on the surface of COP-PAC particles. COP-PAC-PB particles were synthesized by reacting PAC particles with iron(III) chloride and potassium ferrocyanide solutions in order, to synthesize PB within the pores of COPs (in situ). COP-PAC-PB particles were analyzed using XRD and FT-IR techniques, and peaks showing the general characteristics of PB were observed, which indicated that PB existed on the surface of COP-PAC-PB particles. PB was synthesized on the surface of the non-reformed groups (PAC and Ox-PAC) using the same method. In addition, UV–vis analysis was performed to compare the characteristics of PB desorbed from the non-reformed and reformed groups immediately after synthesizing and washing them. In the non-reformed groups (PAC-PB and Ox-PAC-PB), a large amount of PB was desorbed while they were washed 6 times. For COP-PAC-PB, however, a small amount of PB was desorbed during the first washing, but no desorbed PB was observed thereafter. The maximum Cs adsorption capacity of COP-PAC-PB particles was 19 mg/g, and its removal efficiency of radioactivity cesium (Cs-137, 60 Bq/kg) was 97.3%. In this study, the surface of PAC particles was effectively reformed using COPs, and an adsorbent to which PB was stably immobilized was developed.

    更新日期:2019-01-15
  • Preparation and tribological properties of hydrothermally exfoliated ultrathin hexagonal boron nitride nanosheets (BNNSs) in mixed NaOH/KOH solution
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Zhan-Sheng Ma, Hong-Liang Ding, Zan Liu, Zhi-Lin Cheng

    The hexagonal boron nitride nanosheets (BNNSs) were successfully exfoliated by combining hydrothermal treatment in mixed NaOH/KOH solution and subsequent sonication process. The morphology and structure of the as-exfoliated BNNS were determined by a series of characterizations, such as XRD, FTIR, Raman, TEM, SEM, HRTEM and AFM. The results demonstrated that the hydrothermal treatment in mixed NaOH/KOH solution served as an important role in exfoliation and the as-exfoliated BNNSs had the ultrathin thickness of ca. 2–3 layers. Additionally, the dispersion and stability of BNNS in base oil was studied. As a promising application, the tribological properties of BNNS as additive in base oil were tested on ball-on-ball configuration. The average friction coefficient and average wear scar diameter of the BNNS-base oil (0.06%) dropped by about 35.7% and 35.2%. Finally, the forming process and anti-wear mechanisms of BNNS were proposed.

    更新日期:2019-01-15
  • Facile synthesis of graphene-Zn3V2O8 nanocomposite as a high performance electrode material for symmetric supercapacitor
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Wei Hau Low, Poi Sim Khiew, Siew Shee Lim, Chiu Wee Siong, Chin Hua Chia, Ejikeme Raphael Ezeigwe

    In order to improve the energy density of the supercapacitor, fabrication of next-generation materials with inimitable morphology and superior electrochemical performance is highly desired. Herein, a novel hybrid electrode material, namely graphene-Zn3V2O8 nanocomposites, were successfully prepared via facile solvothermal process followed by thermal annealing treatment. Graphene sheets were synthesised through the eco-friendly liquid phase exfoliation approach with optimised ethanol to water volume ratio (2:3). Optimisations on the weight ratio between the graphene and Zn3V2O8 were performed to determine the synergistic effect between them. The morphogenesis of the graphene-Zn3V2O8 nanohybrid manifests “sheet on sheet” nanostructures that intertwined with each other to form a 3D network architecture, which provides sufficient electroactive sites and shortens the ions diffusion pathway, leading to eminent electrochemical properties. The electrochemical properties of these materials were evaluated by cyclic voltammetry and galvanostatic charge-discharge tests in 2 M KOH aqueous electrolyte. Among the nanocomposites studied, G-3ZVO (weight ratio of 1:3) exhibited a specific capacitance of 564 Fg-1 at 0.8 Ag-1, outstanding rate capability and good cycling stability even after 5000 cycles. Furthermore, this symmetrical supercapacitor delivered an impressive energy density of 78 Wh/kg at power density of 75.5 kW/kg.

    更新日期:2019-01-15
  • High-sensitive optical temperature sensing based on 5D1 emission of Eu3+ in YVO4
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Shaoshuai Zhou, Changkui Duan, Min Yin, Shoubao Zhang, Chao Wang

    By studying the temperature-induced red-shift of the VO charge transfer band (CTB) edge in YVO4:10% Eu3+, we demonstrate a high-sensitive strategy for optical temperature sensing using the combination of the temperature-induced enhancement of the excitation in the tail of the CTB and the thermal population of 5D1 state of Eu3+. Under a constant 358 nm excitation, the integrated emission intensity corresponding to 5D1 → 7F1 transition of Eu3+ exhibits drastic temperature dependence ranging from 300 to 480 K. A high relative sensitivity SR was obtained to be 3923/T2. Temperature cycling tests were performed to evaluate the reusability and feasibility as temperature sensors. Our results indicate the potential use of the proposed strategy for high performance optical thermometry.

    更新日期:2019-01-15
  • Effect of thermal condensation temperature on electrochemical capacitive properties of g-C3N4 supported on reduced TiO2 nanowires/nanotubes array
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Samira Yousefzadeh

    In this work, effect of processing temperature in electrochemical capacitors was investigated for g-C3N4. The g-C3N4 materials (CN) were synthesized by thermal condensation of melamine precursor at different temperature (450, 550 and 650 °C). Then, the g-C3N4 materials were deposited on electrochemically reduced TiO2 nanowires/nanotubes arrays (rTWTA)/Ti substrate. The g-C3N4/rTWTA/Ti electrodes were used as supercapacitor electrodes. Morphology, crystal structure and chemical composition of the g-C3N4/rTWTA/Ti electrodes were studied by FESEM, XRD, FTIR and elemental analysis. Based on galvanostatic charge/discharge measurements, the CN(450)/rTWTA/Ti electrode exhibited the highest specific capacitance up to 22 mF/cm2 at 0.3 mA/cm2 with long cyclic durability at 96.8% capacitance retention after 500 cycle. This effect was attributed to the existence of higher nitrogen content, more active sites, the improved hydrophilicity and three-dimensional morphology of the CN(450)/rTWTA/Ti electrode as compared to the other electrodes. This research introduces the optimum thermal condensation temperature of the melamine for synthesis of the g-C3N4 with great potentials in supercapacitors.

    更新日期:2019-01-15
  • Directional solidification of Fe-Al-Ta eutectic by electron beam floating zone melting
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Chunjuan Cui, Chiqiang Ren, Yanyun Liu, Songyuan Wang, Haijun Su

    Fe-Al-Ta eutectic composites have been paid more attentions for high temperature application. Nevertheless, still there is a lack of research on microstructural characteristics and crystal growth mechanism of this eutectic obtained by high temperature gradient directional solidification technique. As such, Fe-Al-Ta eutectic composites were prepared by high temperature gradient electron beam floating zone melting technique in the present paper. Microstructures, solid/liquid interface morphologies and preferential orientations of the Fe-Al-Ta eutectic composites at different solidification rates were studied. Moreover, effect of interface perturbation wavelength on stability of the solid/liquid interface was calculated according to M-S theory and Kurz-Fisher model, respectively. These are consistent with the experimental results well.

    更新日期:2019-01-15
  • N-doped reduced graphene oxide supported Cu2O nanocubes as high active catalyst for CO2 electroreduction to C2H4
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Hui Ning, Qinhu Mao, Wenhang Wang, Zhongxue Yang, Xiaoshan Wang, Qingshan Zhao, Yan Song, Mingbo Wu
    更新日期:2019-01-15
  • Chemically dealloyed Fe-based metallic glass with void channels-like architecture for highly enhanced peroxymonosulfate activation in catalysis
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    J.C. Wang, S.X. Liang, Z. Jia, W.C. Zhang, W.M. Wang, Y.J. Liu, J. Lu, L.C. Zhang
    更新日期:2019-01-15
  • Nanocrystallization, good soft magnetic properties and ultrahigh mechanical strength for Fe82-85B13-16Si1Cu1 amorphous alloys
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    L.L. Pang, A. Inoue, E.N. Zanaeva, F. Wang, A.I. Bazlov, Y. Han, F.L. Kong, S.L. Zhu, R.B. Shull

    New Fe82-85B13-16Si1Cu1 amorphous alloys with low B content and high B/Si content ratios were synthesized by melt spinning for developing good soft magnetic and high strength materials. The crystallization occurs through two stages and the first-stage onset temperature increases from 673 K to 705 K with increasing B content, while the second-stage temperature remains nearly constant. The first and second stages are due to the precipitation of the α-Fe(Si) phase with a size of about 30 nm and the decomposition of the remaining amorphous phase to α-Fe(Si)+Fe3B+Fe2B, respectively. The Fe-based alloys exhibited good soft magnetic properties both in annealed amorphous and nanocrystallized amorphous+α-Fe(Si) phases. The saturated magnetic flux density, coercivity and permeability at 1 kHz are 1.7 T, 4.92 A/m and 7100, respectively, for the annealed amorphous 14B alloy and 1.74 T, 5.62 A/m and 10100, respectively, for the nanocrystallized 13B alloy. The Vickers hardness (Hv) is 803–867 for the as-spun state and it increases with decreasing B content. The Hv increases significantly by crystallization to α-Fe+amorphous phases and reaches 997–1550 for the alloys annealed at 693–763 K just before Tx2. The ultrahigh Hv is presumably due to the combination of fine nanoscale mixed phases, high volume fraction of α-Fe(Si) without internal defects and the enrichment of B into the remaining amorphous phase. Such ultrahigh Hv have not been obtained for Fe-based amorphous and crystallized alloys before and the addition of 1%Cu is essential for the ultrahigh Hv and the amorphous phase formation for the Fe-rich 85%Fe alloy. The new Fe-based alloys are encouraging as future soft magnetic and ultrahigh strength materials with low material cost.

    更新日期:2019-01-15
  • Growth of single crystalline GePb film on Ge substrate by magnetron sputtering epitaxy
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Xiangquan Liu, Jun Zheng, Lin Zhou, Zhi Liu, Yuhua Zuo, Chunlai Xue, Buwen Cheng

    This paper reports the synthesis of single-crystalline GePb alloy films on a Ge(100) substrate by magnetron sputter epitaxy. The as-grown GePb alloy films possess high crystalline quality and no dislocations, as revealed by X-ray diffractometry, transmission electron microscopy. The Pb composition of the GePb alloy was about 0.4% at the growth temperature of 250 °C and it decreased with increasing substrate temperature up to 400 °C. The thermal stability of the GePb alloy was studied using Raman spectra and atomic force microscopy (AFM)results, and it was observed that Pb segregated from the GePb alloy above 400 °C. The successful growth of single-crystal GePb lays the foundation for future GePb device fabrication.

    更新日期:2019-01-15
  • Microstructure and properties of carbon nanotubes-reinforced magnesium matrix composites fabricated via novel in situ synthesis process
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Haipeng Li, Xibin Dai, Lixin Zhao, Baoe Li, Hongshui Wang, Chunyong Liang, Jiawei Fan
    更新日期:2019-01-15
  • Process optimization, microstructures and mechanical properties of a Cu-based shape memory alloy fabricated by selective laser melting
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Jian Tian, Wenzhi Zhu, Qingsong Wei, Shifeng Wen, Shuai Li, Bo Song, Yusheng Shi
    更新日期:2019-01-15
  • 更新日期:2019-01-15
  • Synthesis of Cu–Co bimetallic nanoparticles using TiN-coated electrodes for glucose-sensing applications
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Pei-Jung Tsai, Kai-Ling Chuang, Chia-Jung Yang, Hui-Ting Lee, Fu-Hsing Lu

    This study focuses on the synthesis of Cu–Co bimetallic nanoparticles (NPs) by electrodeposition on conductive TiN-coated electrodes for nonenzymatic glucose-sensing applications. By changing the (Cu/Co)sol. ratio in electrolytes, the atomic concentrations and particle sizes of the Cu–Co NPs over the TiN-coated substrates were tailored. It was easier to incorporate Cu (which exhibits a higher reduction potential) into the NPs than Co. The bimetallic features of Cu–Co NPs were verified by investigating the energy-dispersive spectroscopy/field-emission scanning electron microscopy and field-emission transmission electron microscopy high-resolution images with the corresponding fast Fourier transform patterns. Even a small amount of bimetallic Cu–Co NPs greatly enhanced the detection sensitivity of glucose because of both the synergistic and nanosize effects. At a [Cu/(Cu+Co)]sol. concentration ratio of 0.5, the glucose sensitivity of the obtained Cu–Co NPs with particle sizes of 50 ± 14 nm reached 1602 ± 92 μA cm−2 mM−1, which is much higher than that of the monometallic Cu or Co NPs and lies in the medium–high regime of reported values from the literature.

    更新日期:2019-01-15
  • 更新日期:2019-01-15
  • Formation and electrochemical properties of petal-Like architectures derived from titanium alloy oxide nanotubes for supercapacitors
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Huimin Cui, Wenqiang Huang, Lizhen Wu, Shikai Cao, Ye Song

    Petal-like architecture TiO2 mixed oxide (PATMO) nanotubes were readily fabricated by anodization of Ti-4Al-0.005B (TA5) alloy followed by chemical etching in phosphoric acid solution. The formation of PATMO can be attributed to the combined effect of the water-assisted crystallization of TiO2 and the dissolution of alumina component in TiO2 mixed oxides during etching process. The specific capacitance for the PATMO annealed at 450 °C in argon is about 6 times greater than that of the nanotube counterparts. The PATMO show excellent rate capability and cycling stability with a maximum specific capacitance of 110.78 F cm−3 at 0.1 mA cm−2.

    更新日期:2019-01-15
  • A novel way to synthesize nitrogen doped porous carbon materials with high rate performance and energy density for supercapacitors
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Xin Hu, YaHui Wang, Bing Ding, Xiaoliang Wu

    We report a novel, facile method for the synthesis of nitrogen doped porous carbon with three-dimensional interconnected porous framework by one-step pyrolysis of the mixture of agar, potassium citrate and urea. The optimized material possesses large specific surface area, interconnected porous framework and massive heteroatom functional group. As an electrode material, it delivers a high specific capacity of 357 F g−1 at 1 A g−1, good rate performance (267 F g−1 at 50 A g−1) and good electrochemical stabilization (95.6% initial capacitance retained after 10,000 cycles) in 6 M KOH solution. Moreover, the as-prepared symmetric system based on NPC electrodes shows an energy density of 24.1 Wh Kg−1 between the voltage ranges of 0–1.8 V in 1 M Na2SO4 solution, comparable with most of reported carbon-based symmetric systems. More immortally, even at a high power density of 12.5 kW kg−1, it still remains an energy density of 12.5 Wh kg−1. Therefore, this paper provides a facile, sustainable method for the synthesis of heteroatom doped three-dimensional interconnected porous carbon materials for high performance supercapacitors.

    更新日期:2019-01-15
  • Determination of multilayer effect evidence on metal carbon-nitride system
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    J.C. Caicedo, A. Guerrero, W. Aperador

    TiCN/TiNbCN multilayers were deposited on silicon substrates by r.f. magnetron sputtering with alternatively changing the sputtering plasma composition between pure Ti + C and Nb elements under a reactive mixture Ar/N2. Bilayer period values varied from nanometric range (15 nm) to higher micrometric range (1.5 μm). The coatings structural and stoichiometric properties were analyzed by HAX-ray, X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and cross-sectional transmission electron microscopy (HRTEM). The multilayer period and relative thickness were clearly determined, and a growth structure was found on the TiCN/TiNbCN multilayers. Additionally, an epitaxial relationship was found between layers inside each columnar crystallite, given by (111)[110]TiCN//(111)[110]TiNbCN. The mechanical properties showed an evolution as function of bilayer period increase under cube-on-cube epitaxial growth effect.

    更新日期:2019-01-15
  • K-doped Na3Fe2(PO4)3 cathode materials with high-stable structure for sodium-ion stored energy battery
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Yongjie Cao, Yao Liu, Deqiang Zhao, Junxi Zhang, Xiuping Xia, Tong Chen, Lai-chang Zhang, Peng Qin, Yongyao Xia

    A novel NASICON-type K0.24Na2.76Fe2(PO4)3 (K0.24NFP) is synthesized via a simple solid-state reaction method. K-doped method can enlarge lattice distance and restrain the structure dilapidation from Na3Fe2(PO4)3 to Na5Fe2(PO4)3. Comparison with undoped-Na3Fe2(PO4)3 (NFP) sample (82.1 mAh g−1), K0.24NFP electrode shows a 101.3 mAh g−1 discharge capacity at 10 mA g−1, which up to 97% of theoretical capacity. As for rate capability performance, a high reversible capacity of 73.6 mAh g−1 at 1000 mA g−1. The cycle stability performance measurement results indicate that the discharge capacity of K0.24NFP electrode is up to 93.7 mAh g−1 after 500 cycles at 100 mA g−1. The excellent electrochemical performance is attributed to the improvement of structural stability and the highest intercalation-deintercalation kinetic of sodium-ions (DNa+ = 3.98 × 10−11) due to K-doped. Hence, the K-doped iron-based phosphate (K0.24Na2.76Fe2(PO4)3) should be a potential cathode material in sodium-ions batteries for scale energy storage.

    更新日期:2019-01-15
  • Template deposition of Sb2S3 for solid-state sensitized solar cells
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Yafeng Xu, Wenyong Chen, Linhua Hu, Xu Pan, Shangfeng Yang, Qing Shen, Jun Zhu

    Unavoidable impurities form in Sb2S3 absorber fabricated by conventional chemical bath deposition method which is harmful to the photovoltaic performance of Sb2S3-sensitized solar cells. To obtain high quality Sb2S3 absorber, a two-step template method is introduced to deposit Sb2S3 on mesoporous TiO2 film. This template method is performed by dipping ZnS-coated TiO2 films in a Sb source solution for several minutes. This low temperature method with short operation time allows large area deposition of Sb2S3. Properties of ZnS and Sb2S3 are systematically studied. X-ray photoelectron spectroscopy confirms the absence of impurities. The optimized Sb2S3 device exhibits a power conversion efficiency (PCE) of 3.69%, with an open-circuit voltage of 0.514 V, a short-circuit current-density of 12.14 mA/cm2, and a fill factor of 59.1% under AM 1.5G illumination which is better than the device fabricated by chemical bath deposition. The PCE of our Sb2S3 devices showed an obvious increase after 1–2 months storage which may be caused by reconstruction of the ZnS/Sb2S3 coating fabricated by partial cation exchange.

    更新日期:2019-01-15
  • Facile synthesis of MOF-derived hollow NiO microspheres integrated with graphene foam for improved lithium-storage properties
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Jinxiao Shao, Hu Zhou, Jianhui Feng, Meizhou Zhu, Aihua Yuan
    更新日期:2019-01-15
  • Extremely toughened Ti-based solid-solution carbide cermets
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Nojun Kwak, Shinhoo Kang, Choongkwon Park, Heung Nam Han

    A new cermet with extremely high toughness of ∼22 MPa m1/2 is designed. The high toughness of the cermet is mainly attributed to its characteristic microstructure, i.e., the even distribution of highly tough ceramic particles, unusual core/rim structure with a low internal strain, and strong bridging ligament. The microstructure and toughness of (Ti,W)C-Ni solid-solution cermets are strongly influenced by the addition of WC, i.e., by the W concentrations in the rim and binder phases. As the WC content increases, the shape of the carbide particles changes from faceted to rounded, and the toughness of the cermets increases sharply. In addition, crack propagation induced by an indentation is altered from the trans-granular mode to the inter-granular mode when the WC content is increased.

    更新日期:2019-01-15
  • Electric field modulated metastable state magnetization in (Fe/Pt)4/PMN-PT multilayers
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Zeyang Wang, Dongxing Zheng, Wanchao Zheng, Yuchen Wang, Chao Jin, Haili Bai

    In multiferroic heterostructures, the magnetization can be manipulated by electric field instead of magnetic field via magneto-electric coupling, which can effectively upgrade the speed of the spintronic devices and decrease the energy cost. In this work, Fe/Pt multilayers were grown on (110) oriented 0.7 Pb-(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) substrates and their magnetic properties were studied. A magnetic metastable state was formed by properly applying a magnetic field before the electric field was applied. After applying electric fields, the magnetic moments rotated nearly 180°, indicating that the magnetic anisotropy modulation was achieved in the Fe/Pt multilayers. Our work shows an effective way to manipulate the magnetic properties in Fe/Pt multilayers, which is meaningful for the application of spintronic devices.

    更新日期:2019-01-15
  • Synthesis and structural characterization of orange red light emitting Sm3+ activated BiOCl phosphor for WLEDs applications
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Pramod Halappa, M.R. Harshitha, C. Shivakumara

    We report, synthesis of orange red light emitting Sm3+ activated BiOCl phosphors at relatively low temperature (400 °C) and shorter duration of 1 h. Rietveld refined results confirmed that all the compounds crystallized in the tetragonal structure with space group P4/nmm (No. 129). Functional group analysis were carried out by Fourier transform infrared (FT-IR) and Raman spectroscopy. The Photo-luminescent (PL) experiment results reveal that, an intense PL transition at 598 nm (4G5/2 → 6H7/2) corresponds to orange red emission at λex = 408 nm. The maximum emission intensity was observed for BiOCl: Sm3+ (3 mol%) phosphor, above this concentration quenching takes place due to charge exchange with neighboring Sm3+ ions. Time resolved fluorescence spectroscopic result reveals that, the decay curve is bi-exponential in nature and having long lifetime (τ = 0.58 ms). The obtained CIE and CCT values suggest that these phosphors having excellent color purity (∼90%) and low correlated color temperature. These results suggest that, Sm3+ activated BiOCl can be a potential red phosphor materials for WLEDs and other optoelectronics applications.

    更新日期:2019-01-15
  • Quasi-in-situ analysis of dependency of deformation mechanism and work-hardening behavior on texture in Mg-2Zn-0.1Ca alloy
    J. Alloys Compd. (IF 3.779) Pub Date : 2019-01-14
    Haoge Shou, Jiang Zheng, Yongfa Zhang, Da Long, Jinsong Rao, Qing Liu

    The influence of crystallographic texture on deformation mechanism and work-hardening behavior of the Mg-2Zn-0.1Ca alloy sheet was investigated via quasi-in-situ slip traces analysis. The results show that the sheet displayed a weakened transverse direction (TD) spread texture. The rolling direction (RD) sample exhibited the highest yield strength (104.3 MPa), while the TD samples exhibit the lowest (68.6 MPa), implying a high dependency of yield strength on texture. A deformation mechanism transition were observed in the RD, 45° and TD samples, i.e. basal slip (ε = 0.5%) → basal slip + non-basal slip (ε = 1.5%) → basal slip + non-basal slip + twinning (ε = 7.5%), and non-basal slip was activated to accommodate the imposed deformation due to the increment in an applied shear stress for basal slip with deformation processing. Additionally, the anisotropy of deformation modes is pronounced. At ε = 0.5%, basal slip primarily operated in the grains with high Schmid Factor (SF ≥ 0.35) in TD sample, while in the RD sample, the SFs for basal slip exhibited a wider distribution and prismatic slip also operated. As strain reached to 7.5%, twinning played more important role in the TD sample than the 45° and RD samples. Moreover, the texture has a substantial influence on work hardening behavior. At ε = 1.5%, work hardening rate was governed by SF distribution for basal slip. The sample with more grains exhibiting low SF for basal slip shows higher WH rate. However, twinning plays an important role in effecting work hardening rate at ε = 7.5%, and consequently the TD sample with the greatest area fraction of twin (ftwin) has the highest work hardening rate.

    更新日期:2019-01-15
  • 更新日期:2019-01-15
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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