
显示样式: 排序: IF: - GO 导出
-
Crystalline and magnetic structure of Ba2CuO3+δ investigated by x-ray absorption spectroscopy and resonant inelastic x-ray scattering Physica C (IF 1.241) Pub Date : 2020-12-31 Roberto Fumagalli; Abhishek Nag; Stefano Agrestini; Mirian Garcia-Fernandez; Andrew C. Walters; Davide Betto; Nicholas B. Brookes; Lucio Braicovich; Ke-Jin Zhou; Giacomo Ghiringhelli; Marco Moretti Sala
Motivated by the recent synthesis of Ba2CuO3+δ (BCO), a high temperature superconducting cuprate with putative d3z2−r2 ground state symmetry, we investigated its electronic structure by means of Cu L3 x-ray absorption (XAS) and resonant inelastic x-ray scattering (RIXS) at the Cu L3 edge on a polycrystalline sample. We show that the XAS profile of BCO is characterised by two peaks associated to inequivalent
-
Vortices in a superconducting two-band disk: Role of the Josephson and bi-quadratic coupling Physica C (IF 1.241) Pub Date : 2021-01-06 C.A. Aguirre; Q.D. Martins; J. Barba-Ortega
This paper shows the effect of the Josephson and bi-quadratic coupling types on the vortex state, the magnetization in a two-band superconducting disk in the presence of an external magnetic field and the effect that the γ value has on the vortex state. This study is based on the two bands Ginzburg-Landau time dependent theory, and the main properties are presented via Ab-Initio of MgB2. The superconducting
-
Fracture analysis for a square crack in a square cross section columnar superconductor Physica C (IF 1.241) Pub Date : 2021-01-14 L.L. Liu; J.Y. Liu; W.J. Feng
In this paper, a square central crack problem is investigated for an infinitely long square cross section superconducting column under electromagnetic forces. The generalized Irie-Yamafuji critical current densities model and the magnetically impermeable crack surface condition are adopted for both the zero-field cooling (ZFC) and the field cooling (FC) activation processes. The distributions of magnetic
-
Wafer-level direct bonding of optimized superconducting NbN for 3D chip integration Physica C (IF 1.241) Pub Date : 2021-01-16 Ye Li; Amir Mirza Gheytaghi; Miki Trifunovic; Yuanxing Xu; Guo Qi Zhang; Ryoichi Ishihara
3D integration has well-developed for traditional CMOS technology operating at room temperature, but few studies have been performed for cryogenic applications such as quantum computers. In this paper, a wafer-to-wafer bonding of superconductive joints based on niobium nitride (NbN) is performed to demonstrate the possibility of 3D integration of superconducting chips. The NbN thin films are deposited
-
Combined effect of flux pinning by three-directional columnar defects in a field- angular region of high-Tc superconductors Physica C (IF 1.241) Pub Date : 2021-01-16 Tetsuro Sueyoshi; Ryusei Enokihata; Yuka Hidaka; Masahiro Irie; Takanori Fujiyoshi; Akane Kitamura; Yasuki Okuno; Norito Ishikawa
We investigated the combined effect of flux pinning by three-directional columnar defects (CDs) in a wide field-angular range of YBa2Cu3Oy thin films, where CDs parallel to the c-axis and CDs crossing at ±θi (θi = 45°, 60° and 80°) relative to the c-axis were installed by 200 MeV Xe-ion irradiations. The three-directional CDs with θi ≤ ±60° form a field angular curve of critical current density Jc
-
Research on Current Carrying Capacity of Bi-2223/Ag Superconducting Tape in the Temperature Range of 75-105 K Physica C (IF 1.241) Pub Date : 2021-01-16 Tianhui Yang; Wenxin Li; Ying Xin; Xiaogang Chen; Chao Yang; Chunzhou Tang; Hui Jin; Wei Hong; Jialing Xiong; Jiaojiao Xu; Gengyao Li; Yan Zhang; Jianing Lu
In order to study the feasibility of the co-transmission of electricity and liquefied natural gas (LNG) based energy fluid, we carried out a project supported by a grant from Chinese national key research and development program, Basic Research on Superconducting DC Energy Pipeline. In this project, a superconducting cable cooled by LNG based mixed energy fluid at temperature around 90 K is proposed
-
Characteristics of cross stiffness with different physical and geometrical parameters in a high-temperature superconductor levitation system Physica C (IF 1.241) Pub Date : 2021-01-14 Yong Yang; Shuaijie Yang; Yunyi Wu
Cross stiffness is usually defined as a change in the vertical force when the levitating body moves a small lateral displacement in a high-temperature superconductor (HTS) magnetic levitation system. In most of the existing research reports, the improvement of the levitation stiffness is usually focused on the radial (lateral) and axial (vertical) stiffnesses. The cross stiffness should be studied
-
Non-equilibrium d− wave pair density wave order parameter in superconducting cuprates Physica C (IF 1.241) Pub Date : 2021-01-12 Mikhail Malakhov; Maxim Avdeev
We investigate the nonequilibrium pair density wave order parameter in a simple microscopic model with the ground state d− wave spatially uniform superconductivity. After pushing the system out of equilibrium by a short-time induced order parameter, the system can exhibit robust free nondecaying oscillations of nonuniform superconducting order. In the weak nonequilibrium regime, the frequency of these
-
Enhanced superconductivity due to d-density waves in cuprates Physica C (IF 1.241) Pub Date : 2021-01-10 Kim Ha; Ri Su-Bok; Pak Sung-Gyu
We present a strong-coupling study of the competition and interplay between the d-density wave (DDW) and d-wave superconducting (DSC) states within the fluctuation-exchange approximation for the two-dimensional Hubbard model. We find the occurrence of a new DDW state with phase fluctuations induced by spin fluctuations above TC. It is shown that in this state the density of states has a pseudogap,
-
Flux pinning in NbSe2 - CrGeTe3 heterostructures Physica C (IF 1.241) Pub Date : 2020-12-04 Darren Nutting; Freddie Withers
We observe a hysteretic superconducting switch effect in NbSe2 - CrGeTe3 superconductor/ferromagnet bilayer structures. The switching effect occurs robustly at perpendicular external magnetic fields between 80
-
Nano-sized amorphous / semi-crystalline boron ratio and external Mg effects on transport and structural properties in MgB2 IMD wires Physica C (IF 1.241) Pub Date : 2020-12-14 Hakan Yetiş; Fırat Karaboğa; Doğan Avcı; İbrahim Belenli
In the present study, Mg diffusion process has been investigated by transport measurements and surface morphology analysis in round MgB2 wires made with internal Mg diffusion (IMD) method. These wires were produced using semi-amorphous boron, nano-sized amorphous boron or mixtures of them via cold drawing process. In addition to the conventional IMD wire production technique, a thin layer of magnesium
-
Flux-dependent evolution of mixed pairing orders in mesoscopic superconducting square loops Physica C (IF 1.241) Pub Date : 2020-12-15 Hui-Qin Zou; Guo-Qiao Zha
Based on a model Hamiltonian including the on-site repulsive interaction among the electrons, we investigate the flux-dependent evolution of mixed pairing orders in mesoscopic superconducting square loops by numerically solving the Bogoliubov-de Gennes equations. The influence of centered hole size on the order modulation is mainly discussed. For the emergent spin-triplet p-wave and subdominant spin-singlet
-
Numerical simulation and analysis of running magnetic resistance in the evacuated tube SS-HTS magnetic levitation system Physica C (IF 1.241) Pub Date : 2021-01-05 Ju Wang; Feinan Cai; Jing Jiang; Lifeng Zhao; Yong Zhao; Yong Zhang
The evacuated tube side-suspended high-temperature superconducting (SS-HTS) magnetic levitation prototype vehicle can run at high speed on a uniform permanent magnet guideway due to the characteristics of magnetic flux pinning. However, permanent magnet guideway with magnetic fluctuations will cause resistance in the running direction of the high-temperature superconducting maglev prototype vehicle
-
Negative nonlocal and local voltages (resistances) in a quasi-one-dimensional superconducting aluminum structure Physica C (IF 1.241) Pub Date : 2020-12-31 V.I. Kuznetsov; O.V. Trofimov
To study a nonlocal electron transport in an aluminum superconducting quasi-one-dimensional structure, we measured negative nonlocal (local) direct current voltages in the structure in a magnetic field near the critical temperature. The structure is a normal-superconducting at Tcn
-
Simplified approach of investigation of binding energy for fermionic pairing in two dimensional Fermi liquid type superconducting materials at finite low temperature Physica C (IF 1.241) Pub Date : 2020-12-08 Soumyadipta Pal; Subarna Datta
Relation between the binding energy of pair of fermions and the magnitude of the attractive interaction between them is investigated theoretically with the help of mean field approximation, for a two-dimensional (2D) Fermi liquid type superconducting material. Here the fermion pair has finite center of mass momentum (CMM). The fermion pair is considered to be formed in the presence of an active Fermi
-
Extended Ginzburg-Landau equations and Abrikrosov vortex and geometric transition from square to rectangular lattice in a magnetic field Physica C (IF 1.241) Pub Date : 2020-12-14 Rami Ahmad El-Nabulsi
In this study, we have constructed an extended version of Ginzburg-Landau theory of superconductivity starting from the exponential non-standard Lagrangian. An extended Ginzburg-Landau coherence length and an extended Ginzburg-Landau parameter emerge in the theory without affecting the Abrikosov's fluxoid quantization law. We have discussed the Abrikosov's periodic vortex lattice problem and we have
-
About the Pressure-Induced Superconducting State of Europium Metal at Low Temperatures Physica C (IF 1.241) Pub Date : 2020-12-10 J.E. Hirsch
In Physical Review Letters 102, 197002 (2009), it was reported that the element Eu becomes superconducting in the pressure and temperature range [84-142GPa], [1.8-2.75K]. The claim was largely based on ac susceptibility measurements. Here I point out that recently reported ac susceptibility measurements on a hydride compound under pressure that appears to become superconducting near room temperature
-
Inverted HTS rectangular patch antennas: Theoretical investigation Physica C (IF 1.241) Pub Date : 2020-12-01 Sami Bedra; Siham Benkouda; Randa Bedra; Tarek Fortaki
In this paper, we propose a full-wave analysis for characterizing the resonant frequencies and bandwidths of high-temperature superconductor inverted microstrip printed on anisotropic substrates. Our proposed approach is based on Galerkin procedure in the Fourier transform domain (FTD) combining with the complex resistive boundary condition. With the use of suitable Green's functions in the FTD, the
-
Preparation of superconducting RuGd-1222 single crystals by partial melting Physica C (IF 1.241) Pub Date : 2020-11-20 Kazuhiro Yamaki; Takashi Mochiku; Keitaro Tezuka; Akinobu Irie
Growth of single crystals of RuGd-1222 ((Gd,Ce)2Sr2RuCu2O10−δ) remains a major challenge, and previous studies have indicated that epitaxial thin films of these compounds exhibit deteriorated superconductivity. We have been working toward the synthesis of RuGd-1222 single crystals using the self-flux and partial melting techniques. In this paper, we report on the synthesis of RuGd-1222 single-crystal
-
Improved superconducting properties of multifilament internal Mg diffusion processed MgB2 wires by rapid thermal processing Physica C (IF 1.241) Pub Date : 2020-11-24 Xiaomei Xiong; Qingyang Wang; Fang Yang; Jianqing Feng; Chengshan Li; Guo Yan; Pingxiang Zhang
6+1-filament MgB2 long wires with high critical current densities were fabricated using an internal Mg diffusion (IMD) process. The effect of high temperature treatment by conventional furnace annealing and rapid thermal processing on the superconducting properties and microstructure of IMD wire was investigated. The rapid thermal processing can improve the superconducting properties of multifilament
-
Estimation Method for AC Loss of Perpendicularly Stacked REBa2Cu3Oy Superconducting Tapes under Magnetic Field Physica C (IF 1.241) Pub Date : 2020-11-26 Hiromasa Sasa; Shun Miura; Masataka Iwakuma; Teruo Izumi; Takato Machi; Akira Ibi
The AC loss occurred in REBa2Cu3Oy (REBCO, RE = rare earth elements, Y, Eu, Gd) superconductor is serious problem in AC applications because it may cause a severe temperature rise of superconducting systems. Therefore, it is necessary to understand the AC loss property of REBCO superconducting tape in detail and to reduce that. As AC application such as motor, the tape is mostly stacked into multi-layer
-
Heat transfer through multi-layer insulation (MLI) Physica C (IF 1.241) Pub Date : 2020-11-25 Masae Kanda; Kazuaki Matsumoto; Sataro Yamaguchi
Multi-layer insulation (MLI) is a crucial component to reduce a heat leak of a cryostat, and it is used for various applications in cryogenics. Its role is significant for the superconducting power transmission line (SCDC) mainly because the ratio of the surface to the volume is large for the conventional cryostat, and the heat leak is a principal source of the loss of SCDC. If we cannot reduce the
-
Performance testing of the iron-based superconductor inserted coils under high magnetic field Physica C (IF 1.241) Pub Date : 2020-11-07 Xinxing Qian; Shili Jiang; Hangwei Ding; Pengcheng Huang; Guihong Zou; Donghui Jiang; Xianping Zhang; Yanwei Ma; Wenge Chen
The iron-based superconductor (IBS) is considered to have a great potential application under high magnetic field. It is one of the important steps to carry out the research on high magnetic field IBS inserted coil in order to promote the practical application of IBS. We developed a type of Ba122 single and double pancake inserted coils with 35 mm outer diameter, and its performance has been tested
-
London superconductivity approach in a time-dependent background Physica C (IF 1.241) Pub Date : 2020-11-07 V. Aguiar; J.P.G. Nascimento; I. Guedes; R.N. Costa Filho
The main goal of this paper is to obtain the exact quantum solutions for charge space in a superconductor with time-dependent parameters using the London approach. We introduce a new quantization scheme for the charge inside a superconductor based on the Lewis and Riesenfeld invariant operator method. From the wave-functions obtained, we calculated the time-dependent uncertainties and the mean energy
-
Leading theories of the cuprate superconductivity: A critique Physica C (IF 1.241) Pub Date : 2020-11-06 Navinder Singh
We present a review of the leading theoretical approaches in the field of cuprate high temperature superconductivity. We start out by defining the problem and ask the question: whether an overarching theory possible (which is capable of explaining not only the mechanism of unconventional superconductivity but also a coherent understanding of the strange metal phase and the pseudogap phase)? If it is
-
Dependences of local density of state on temperature, size, and shape in two-dimensional nano-structured superconductors Physica C (IF 1.241) Pub Date : 2020-11-06 Saoto Fukui; Zhen Wang; Masaru Kato
In this paper, we investigate a local density of state (LDOS) in a two-dimensional nano-structured superconductor. We solve the Bogoliubov-de Gennes equations self-consistently with the two-dimensional finite element method. In the nano-structured superconductor, the LDOS as a function of energy has many discrete peaks. Discretization of the LDOS comes from discretization of energy levels due to the
-
Pinning mediated field penetration and complex susceptibility in inhomogeneous superconductors Physica C (IF 1.241) Pub Date : 2020-11-02 S. Roy; Ajay Kumar Ghosh
The penetration of the magnetic field in a network consisting of the superconducting grains and intergranular region depends not only on the applied external magnetic field but also on the underlying pinning force density and fraction of the superconducting grains in the sample. Considering the underlying pinning force density in the form of the repetitive Gaussian (RG) nature we have solved the critical
-
Current density distribution in resistive fault current limiters and its effect on device stability Physica C (IF 1.241) Pub Date : 2020-11-07 M. Farokhiyan; M. Hosseini; A. Kavousi-Fard
The increase of current uniformity along of a Resistive type Superconductor Fault Current Limiter (R-SFCL) in the design of this type of limiters is well perceived as an important issue. The non-uniform distribution of current in R-SFCL only increases the current in some superconducting regions, as a result, in the fault conditions, only certain parts of the superconductor undergo a phase change that
-
Quasiparticle scattering time in NbN superconducting thin films Physica C (IF 1.241) Pub Date : 2020-09-24 Lu Zhang; Lixing You; Wei Peng; Zhen Wang
A deep understanding of the quasiparticle inelastic scattering rate in superconducting materials is beneficial for the further development of ultrasensitive and rapid superconducting detectors. From the flux flow instability in current–voltage characteristics of NbN superconducting films, we have derived the critical vortex velocity (ʋ*) and quasiparticle inelastic scattering time (τE) of the 10- and
-
Influence of the Al thickness of Nb/Al-AlOx/Nb Josephson junction on the magnetic field dependence of the Josephson current Physica C (IF 1.241) Pub Date : 2020-08-28 Kazuki Kobayashi; Akiyoshi Nakayama; Susumu Abe; Norimichi Watanabe
We have fabricated Nb/Al-AlOx/Nb Josephson junctions and have measured their current-voltage characteristics and the two-dimensional magnetic field dependence of the Josephson current. When the external magnetic fields (Hx, Hy) parallel to the junction plane are applied to the Josephson junction from two directions, two Fraunhofer diffraction patterns are observed in the (Hx, Hy) plane. In this study
-
AC losses of a like-corc conductor using accelerated 3D T-A model Physica C (IF 1.241) Pub Date : 2020-09-21 Yueyin Wang; Yinshun Wang; Defu Wei; Tie Guo; Yiran Meng; Jiuke Wang; Changtao Kan
A like-CORC based on the Quasi-isotropic (Q-IS) conductor, so called Q-IS_CORC consisting of CORC and Q-IS making from 2 G high temperature superconducting (HTS) tapes, is investigated in terms of AC losses by combining experimental with numerical methods. A new type of a like-CORC conductor is presented and is good bending performance as well as easy to manufacture in long lengths. Moreover, this
-
Electromagnetic performance analysis of linear vernier machine with PM and HTS-Bulk Physica C (IF 1.241) Pub Date : 2020-08-20 N. Arish
Today, superconductor materials are widely used in electric machines because of their unique properties. This has been always a question for designers and researchers whether super-conductors can be a good substitute for Permanent Magnet (PM) or not. In this paper, the performance of a dual stator linear vernier machine under identical conditions in the presence of High-Temperature Superconductor Bulk
-
Superconducting transition in resistivity and magnetization of the solid solution (Pb0.4Sn0.6)0.8In0.2Te Physica C (IF 1.241) Pub Date : 2020-09-01 D.V. Denisov; N.Yu. Mikhailin; D.V. Shamshur; R.V. Parfeniev
The temperature and magnetic field dependences of electrical resistivity ρ(Т, Н) and magnetization m(Т, H) of the semiconductor solid solution (Pb0.4Sn0.6)0.8In0.2Te were studied in the temperature range T = 2 K - 300 K (including the region of the superconducting transition of the compound T ≤ 4 K) and in magnetic fields H ≤ 140 kOe. The critical parameters of superconducting transition were determined:
-
Simulation and visualization of the interference phenomena inside DC SQUID with interferometric circuit model Physica C (IF 1.241) Pub Date : 2020-08-31 Yongliang Wang; Guofeng Zhang; Shulin Zhang; Xiaoming Xie
Flux modulated static current-voltage characteristics are the basis of DC SQUID being the flux-to-voltage convertor utilized in high-performance magnetic field measurement systems. Those static behaviors are the results of the internal quantum interference between two Josephson junctions. However, the interferometric working principle and the interference phenomena are difficult to be intuitively visualized
-
Josephson current between two p-wave superconducting nanowires in the presence of Rashba spin-orbit interaction and Zeeman magnetic fields Physica C (IF 1.241) Pub Date : 2020-08-28 E. Nakhmedov; B.D. Suleymanli; O.Z. Alekperov; F. Tatardar; H. Mammadov; A.A. Konovko; A.M. Saletsky; Yu.M. Shukrinov; K. Sengupta; B. Tanatar
Josephson current between two one-dimensional nanowires with proximity induced p-wave superconducting pairing is calculated in the presence of Rashba spin-orbit interaction, in-plane and normal magnetic fields. We show that Andreev retro-reflection is realized by means of two different channels. The main contribution to the Josephson current gives a scattering in a conventional particle-hole channel
-
Transmittance spectrum in a semiconductor-superconductor quasi-periodic Thue-Morse one-dimensional photonic crystal Physica C (IF 1.241) Pub Date : 2020-09-09 Francis Segovia-Chaves; Herbert Vinck-Posada; Edgar A. Gómez
Based on the transfer matrix method and the two-fluid model, this study seeks to calculate the transmittance spectrum of a quasi-periodic one-dimensional photonic crystal (PC) composed of semiconductor (GaAs) and superconductor (HgBa2Ca2Cu3 O8+δ) layers. In particular, the arrangement of the PC layers follows a Thue-Morse sequence with a given periodicity. The critical temperature of the superconductor
-
Crack problem in a slab superconductor under flux creep and viscous flux flow after zero field cooling Physica C (IF 1.241) Pub Date : 2020-09-22 Yufeng Zhao; Pengdong Ji
A relatively complex model is developed to estimate the effect of the electromagnetic force on fracture behavior in a slab superconductor with a center-situated crack, where the viscous flux flow and flux creep have been considered. The effects of the viscous flux flow and flux creep on the stress intensity factors and flux profiles are discussed for the descending field. The results indicate that
-
The thermal-hydraulic response of the superconducting outsert during the trip of the resistive magnet in the hybrid magnet system of the CHMFL Physica C (IF 1.241) Pub Date : 2020-09-26 Shili Jiang; Xinxing Qian; Hangwei Ding; Wenge Chen; Zhiyou Chen; Junjie Li; Pengcheng Huang; Guihong Zou; Siyue Chen; Donghui Jiang; Guangli Kuang
The hybrid magnet system has been completed the commissioning and be ready to serve users at the High Magnetic Field Laboratory of the Chinese Academy of Sciences (CHMFL) in Hefei, China. The hybrid magnet consists of a 28 MW, 34 T resistive insert coils set nested inside of a 800 mm bore 11 T superconducting outsert magnet. The outsert coils are wound with high JC Nb3Sn/Cu cable-in-conduit conductor
-
Structural Analysis of 2G HTS Tapes under Different Loading Conditions for HTS Power Cable using Finite Element Modeling Physica C (IF 1.241) Pub Date : 2020-09-22 Ipsita Das; Vineet Sahoo; V.V Rao
In High Temperature Superconducting (HTS) power cable, HTS tapes are wound helically around a circular former and are subjected to different types of mechanical loads during manufacturing, transportation and installation of cable. The strain developed within the HTS tape during these processes may affect the superconducting properties of the tape. In the present work, 3D structural finite element (FE)
-
Electrical design and structure optimization of 10 MW fully superconducting wind turbine generators Physica C (IF 1.241) Pub Date : 2020-09-20 Yuanyuan Xu; Lian-Tong An; Bao-Zhu Jia; Naoki Maki; Mitsuru Izumi
In this paper, two types of conceptual structures of 10 MW fully superconducting offshore wind turbine generators (FSWTG) with an efficient electrical design method are presented. Four types of generator models, Gen. A - D, are compared according to different armature winding structures, and it's found that Gen. A is the preferable one. Optimization of the main generator parameters reveals that 36
-
Topological defect states in mesoscopic chiral p-wave superconducting rectangles Physica C (IF 1.241) Pub Date : 2020-09-12 Xue-Xue Zhang; Guo-Qiao Zha
In the framework of the microscopic Bogoliubov-de Gennes theory, we investigate the topological defect states in mesoscopic chiral p-wave superconducting rectangles. In the absence of applied magnetic field, stable multi-domain-wall states containing two or more domain walls can be obtained with the increase of the aspect ratio of the rectangle at zero temperature. When the external field is applied
-
Numerical study on the model of HTS bearing by coupling the magnetic scalar potential and magnetic field intensity Physica C (IF 1.241) Pub Date : 2020-08-25 Xiang Guan; Yincai Zou; Jin Shang; Xing Bian; Jihao Wu; Qing Li
HTS magnetic bearing is one of the important applications of HTS suspension system. It is a relatively complicated problem to describe the relative motion of superconductor and permanent magnet in the numerical calculation of HTS suspension system. For this problem, firstly, this paper analyzes the characteristics and limitations of the existing methods, and then proposes a new solution: using the
-
Magnetic force and stiffness performances of Maglev system based on multi–surface arrangements with three-seeded bulk YBaCuO superconductors Physica C (IF 1.241) Pub Date : 2020-08-20 K. Ozturk, M. Abdioglu, Z. Karaahmet
We have designed a multi–surface HTS (high temperature superconductor with three seeded bulk YBaCuO) Maglev system by increasing the YBaCuO number while decreasing the PM number in HTS–PMG system to enhance the loading capacity and stability of the superconducting Maglev system while reducing the fabrication cost. By this study, a detailed investigation on the magnetic levitation force, guidance force
-
Enhancement of Bc2 and Birr in bulk MgB2 superconductors with SnO2 Additions Physica C (IF 1.241) Pub Date : 2020-08-19 Danlu Zhang, Michael D. Sumption, Edward W. Collings, C.J. Thong, Matt A. Rindfleisch
Three (MgB2)1-x(SnO2)x samples with x ranging from 0 to 5 wt% were prepared by the in situ route to study the effect of tin dioxide additions on the superconducting properties of MgB2 bulk materials. All of the reacted samples were slightly Mg deficient although the starting Mg:B precursor powder ratio was 1:2. A heat treatment (HT) temperature of 700 °C with a dwell time of 30 min was used. XRD results
-
Various effects of aliphatic amino acids on the critical current of the MgB2 superconductor Physica C (IF 1.241) Pub Date : 2020-08-19 J.-C. Grivel, J. Cui, A. Consuelo-Leal
Carbon-doped MgB2 polycrystalline bulk samples were prepared by reacting mixtures of Mg and B powders, with and without 0.5 wt.% of the amino acids glycine, alanine, valine, leucine or isoleucine. The amount of carbon introduced into the MgB2 structure depends on the amino acid and is surprisingly higher for glycine, which has the lowest carbon content among the aliphatic amino acids. The critical
-
An inertial model of vortices to explain the extreme sensitivity of hexatic vortex fluid to low frequency ac excitation Physica C (IF 1.241) Pub Date : 2020-08-17 Surajit Dutta, Pratap Raychaudhuri
Recently, it has been demonstrated that the Hexatic vortex fluid realized in 2-dimensional vortex state of a very weakly pinned amorphous MoGe thin film is extremely sensitive to external ac excitation. A large amplification of resistance is observed when the sample is exposed to external electromagnetic radiation or a small ac current is superimposed with the subcritical measuring dc current. The
-
Study of transport and elastic properties of YBCO superconductor by inclusion of GnPs Physica C (IF 1.241) Pub Date : 2020-08-17 Bibekananda Sahoo, Dhrubananda Behera
The variation in superconducting and elastic parameters of YBa2Cu3O7-δ (YBCO) superconductor due to addition of Graphene nanoplatelets (GnPs) was examined. All the composite samples (1-x) YBCO + x GnPs (x = 0.1, 0.3, 0.5, 0.7 and 0.9%) were synthesized by conventional solid state reaction route. The structural and morphological characterizations of composite samples were investigated through the X-ray
-
Modelling analysis of periodically arranged high-temperature superconducting tapes Physica C (IF 1.241) Pub Date : 2020-08-16 Jianxun Jin; Runtao Zhang; Zhiwei Lin; Youguang Guo; Jianguo Zhu; Xiaoyuan Chen; Boyang Shen
The operation of a high-temperature superconducting (HTS) device is strongly related to its electromagnetic environment. It is necessary to study the electromagnetic interaction of proximity HTS tapes placed in the horizontal or vertical direction, which is important for the design and optimization of HTS devices. This paper presents a numerical model of periodically arranged HTS tapes using the finite
-
Lateral vortex motion in highly layered electron-doped superconductor Nd2−xCexCuO4 Physica C (IF 1.241) Pub Date : 2020-08-07 O.E. Petukhova, M.R. Popov, A.S. Klepikova, N.G. Shelushinina, A.A. Ivanov, T.B. Charikova
The carrier transport and the motion of a vortex system in the electron-doped high-temperature superconductors Nd2−xCexCuO4 in underdoped and optimally doped (x = 0.135, 0.145, 0.15) regions, in the area of the evolution from antiferromagnetic to superconducting order were investigated. To study the anisotropy of the transport properties of highly layered NdCeCuO system we have synthesized Nd2−xCexCuO4+δ/SrTiO3
-
Design of extensible superconducting multiplexer with modular structure to overcome the limit of wafer size Physica C (IF 1.241) Pub Date : 2020-07-29 Zhang Teng, Lingling Zhong, Guoqiang Chen, Tiege Zhou, Li Gong, Ming He, Xu Zhang
In this paper, a new compact superconducting multiplexer with an extensible modular structure is proposed. The multiplexer consists of a common input feeder and multiple bandpass filters. The common feeder is realized by a transmission line with a characteristic impedance of 50 ohms. Compared with the conventional multiplexer, the proposed length of the common feeder is extensible, making it feasible
-
Design of miniature high-temperature superconducting quadruplexer with wide stopband suppression Physica C (IF 1.241) Pub Date : 2020-07-23 Hongwei Yue; Hanxue Tang; Litian Wang; Li Gong; Cheng Li; Baolin Wei; Qinglian Xie; Jihai Duan
In this paper, a compact high temperature superconducting (HTS) multiplexer with improved out-of-band suppression and wide stopband attenuation is proposed. Each passband can be individually synthesized and conducted by using distributing coupling scheme without any additional matching network. The proposed quadruplexer is constructed by four sets of four order bandpass filters (BPFs) with compact
-
Improved biaxial texture of tri-layer YBCO/CaTiO3/YBCO films using an all chemical solution deposition method Physica C (IF 1.241) Pub Date : 2020-07-23 Chunyuan Zhang, Xiaoyan Du, Huiliang Zhang
The chemical solution deposition (CSD) is one of the most appealing routes for the growth of high-quality YBa2Cu3O7-δ (YBCO) films due to its advantages of low cost and high efficiency. However, as with other preparation methods such as pulsed laser deposition (PLD), the critical current densities (JC) of YBCO films prepared by the CSD method also dramatically decrease with increasing film thickness
-
Quantitative characterization of nonlinear impedance and load characteristic of 50-kW-class fully superconducting induction/synchronous motor Physica C (IF 1.241) Pub Date : 2020-07-15 T. Nakamura, M. Okuno, M. Yoshikawa, Y. Itoh
This paper reports an optimal technique to design a fully superconducting motor. A 50-kW-class fully superconducting induction/synchronous motor with both rotor and stator windings was fabricated from bismuth–strontium–calcium–copper-oxide (BSCCO) tapes and quantitatively characterized. The toroidal structure was adopted for the stator windings in order to increase their critical current in the iron
-
Effect of proton fluence on the superconducting properties of MgB2. irradiated with protons of high energy Physica C (IF 1.241) Pub Date : 2020-07-15 V. SANDU, A.M. IONESCU, I. IVAN, L. CRACIUN, G. ALDICA
Effects of proton irradiation on the superconducting properties of sintered MgB2 samples were investigated as a function of proton fluence at fixed energy. All experimental data suggest that critical current densities, irreversibility field and creep activation energy are enhanced because of the complex disorder, which mainly affects the grain boundaries, brought on the crystalline structure by the
-
Evaluation of critical current in junction of superconductors with crack using finite element method Physica C (IF 1.241) Pub Date : 2020-07-14 Ruizhe Zhang, Yushi Kinoshita, Edmund Soji Otabe, Tomoyuki Akasaka, Atsushi Ishihara, Masaru Tomita
In the present study, in order to clarify the electrical and mechanical properties of the junction of superconducting wires, a junction was numerically simulated using the finite element method, and the electrical and mechanical properties were evaluated. We used a 1 µm-thick YBa2Cu3O7−δ superconducting coated conductor to act as a superconducting wire and joined two films together for current density
-
Improvement of superconducting properties by chemical pressure effect in Eu-doped La2-xEuxO2Bi3Ag0.6Sn0.4S6 Physica C (IF 1.241) Pub Date : 2020-07-12 Rajveer Jha, Yosuke Goto, Ryuji Higashinaka, Akira Miura, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshikazu Mizuguchi
We have investigated the substitution effect of Eu on the superconductivity in La2-xEuxO2Bi3Ag0.6Sn0.4S6. Recently, we reported an observation of superconductivity at 0.5 K in a layered oxychalcogenide La2O2Bi3AgS6. The Sn doping at the Ag site was found to raise the superconducting transition temperature, Tc, to 2.5 K in La2O2Bi3Ag0.6Sn0.4S6. To further improve the superconducting properties, we have
-
First-principles investigation of the superconducting properties of MgXB4 (X = Al, Li, Na, K) Physica C (IF 1.241) Pub Date : 2020-07-12 Yongbo Li, Honggang Chen, Guangyu Han, Xiaopeng Zhao
The discovery of superconductivity of MgB2 has attracted considerable research attention. Further exploration and discovery of MgB2-like superconductors are important to determine the properties of MgB2 and enhance our understanding of the superconducting mechanism. Four MgB2-like MgXB4 (X = Al, Li, Na, K) superconductors based on an MgB2 structure were designed in this study. The electronic structure
-
Hybrid acousto-electromagnetic metamaterial superconductors Physica C (IF 1.241) Pub Date : 2020-07-11 Igor I. Smolyaninov, Vera N. Smolyaninova
Recent theoretical and experimental studies demonstrated that an electromagnetic metamaterial approach is capable of drastically increasing the critical temperature Tc of composite metamaterial superconductors. This progress was achieved by engineering the frequency-dependant dielectric response function of the metamaterial. Here we further extend this approach by introducing the concept of hybrid
-
Macroscopic residual stress and properties in different YBa2Cu3O7-x heterogeneous systems Physica C (IF 1.241) Pub Date : 2020-07-11 Jingfeng Yu, Fang Li, Jiangwei Fan, Suleman Muhammad, Yam Prasad Dahal, Zhuli Zhang, Sansheng Wang
Residual stress and internal strain induced by interface lattice mismatches between YBa2Cu3O7-x thin films and substrates causes variation on microstructures and superconducting properties. In this research, we investigated small misfit misalignments of YBa2Cu3O7-x thin films prepared on (LaAlO3)0.3-(Sr2AlTaO6)0.7 (LSAT), LaAlO3 and SrTiO3 substrates, and their resulting effects on their superconducting
-
Static properties of STM tip in response to magnetic field Physica C (IF 1.241) Pub Date : 2020-07-11 A. Hasnat
A nano size pyramidal superconducting tip is characterized theoretically. Vortex states are achieved in the framework of three-dimensional (3D) numerical discretization of Ginzburg-Landau (GL) formalism. Systematic investigation is performed according to the geometric parameters of the tip and different GL parameter κ. Meissner state and critical field of the tip are obtained in the presence of external