Crystal structure refinement, optical properties, dielectric response, and impedance spectroscopy of Ni2+-Co2+ substituted bismuth copper titanate (BCTO)
Graphical abstract
Introduction
Decades of considerable attention has been given to the synthesis and characterization of nanomaterials because of the need to produce efficient and portable electronics devices [[1], [2], [3], [4], [5], [6]]. The discovery of the perovskite material calcium copper titanate (CCTO) having chemical composition CaCu3Ti4O12 and giant dielectric constant by Subramanian et al., in 2000 has prompted renewed interest in materials with giant dielectric constant [7]. This is as a result of the fact that advancement in miniaturization of electronics devices, supercapacitors, actuators, catalysis and memory devices requires nanomaterials with giant dielectric constant greater than 1000 [[8], [9], [10], [11], [12]]. Unlike ferroelectric materials such as barium titanate (BaTiO3), CCTO do not show ferroelectric properties even though they exhibit giant dielectric constant ( for polycrystalline and for single crystals) from 100 to 600 K in the kilohertz region [[13], [14], [15]]. Although the internal barrier layer capacitance (IBLC) model is commonly accepted as the origin of the giant dielectric constant observed in CCTO ceramic, the origin of the giant dielectric constant of this perovskite material has remained a subject of debate among the scientific community [16]. This is further supported by impedance spectroscopy where the perovskite material was observed to exhibit scenario where insulating grain boundaries separates the semiconducting grains, similar to single-step internal barrier layer capacitor [17]. Additionally, transmission electron microscopy (TEM) micrographs and nonlinear current-voltage behaviour of CCTO indicates that the electrical properties of CCTO are greatly influenced by grain boundaries [18].
Bismuth copper titanate (BCTO) (Bi2/3Cu3Ti4O12) as a member of the titanate family with general formula ACu3Ti4O12 (where A = Ba, Ca, Sr, Gd2/3, Pr2/3, Y2/3, Bi2/3 or La2/3) has been rarely explored. Although some researchers have attempted to synthesized BCTO [[19], [20], [21]], the challenge of obtaining giant dielectric constant while maintaining reasonable low dielectric loss still remains an issue [22]. L. Yang et al. employ solid state reaction method and synthesized BCTO, high dielectric constant of approximately 3.3 10 5 at 1 kHz was obtained [23]. P. Gautam et al. observed a dielectric constant value of 13.94 103 and dielectric loss of approximately 2.4 at 503 K in a Bi2/3Cu3Ti4O12/Bi3LaTi3O12 nanocomposite [24]. P. Gautam et al. synthesize BCTO electroceramic via semi-wet route, the prepared samples shows dielectric constant value of 2.9 × 104 and dielectric loss above 10 [25]. However, these values of the dielectric losses are very high for practical application. In this research, we report on the influence of Ni2+-Co2+ substitution on the properties of BCTO electroceramic prepared using sol-gel autocombustion method. The prepared BCTO electroceramic were characterized via XRD, FTIR, FESEM/EDX, UV–vis NIR spectroscopy and LCR meter.
Section snippets
Experimental details
Sol-gel autocombustion method was used to prepare Bi2/3Cu3-2xNixCoxTi4O12 (x = 0.0, 0.1, 0.2) using high purity (99%–99.5%) AR grade starting material such as Bi(NO3)3·5H2O (CDH), Ni(NO3)2·6H2O (LOBA Chemie), Cu(NO3)2·3H2O (LOBA Chemie), Co(NO3)2·6H2O (LOBA Chemie), TiO2 (LOBA Chemie) and C6H8O7 (LOBA Chemie). Required amount of the starting material in stoichiometric ratios were dissolved in double distilled water to form an aqueous solution, citric acid was added as fuel to the aqueous
Characterization techniques
The structural and phase analysis of the prepared samples was carried out using X-ray diffraction pattern recorded using Bruker AXS D8 advance diffractometer having Cu–K radiation in the range 20–80. Investigation of attached functional groups and characteristics signature of the prepared BCTO electroceramic was carried out in the range 4000–400 cm−1 using FTIR spectrophotometer (Nicolet FTIR model-8400S) by preparing thin pellets of KBr with the prepared samples in the ratio 10:1
Structural and phase analysis
Fig. 1 shows the XRD patterns of Bi2/3Cu3-2xNixCoxTi4O12 (x = 0.0, 0.1, 0.2) calcined at 900 ̊C for 7 h. The observed peaks in the XRD spectra have been indexed according to standard data (JCPDS card: 80–1343), it was found that the prepared samples are of a single phase with perovskite structure and space group Im-3 with the absence of secondary phase such as CuO, Cu2O, or TiO2 and other related oxides [14]. The lack of secondary phase in the XRD spectra indicates that the substituted cations
Conclusion
Ni2+-Co2+ substituted Bi2/3Cu3Ti4O12 electroceramic have been successfully synthesized using sol-gel autocombustion method. The prepared electroceramics were subjected to various characterizations and subsequent data analysis using different software, the following observations have been made.
- 1.
The XRD spectra of the prepared electroceramic show explicit peaks of BCTO electroceramic with single crystalline phase, cubic perovskite structure and space group Im-3. CuO and TiO2 secondary phases have
Author credit statement
Tchouank Tekou Carol T., J. Mohammed, and A. K. Srivastava performed the experiment and discussion of the data.
Sanjay Mishra participated in the calculations and fitting of the data.
Sachin Kumar performed the XRD characterization.
Richa Bhargava and Shakeel Khan performed the dielectric characterization and contributed to the analysis of the dielectric data.
Declaration of competing interest
The authors declare no conflict of interest.
Acknowledgement
The authors would like to thank Materials Research Centre, Malaviya National Institute of Technology, Jaipur, India, for FESEM/EDX characterization and Sophisticated Test and Instrumentation and Centre, Cochin University of Science and Technology, Kerala, India, for UV–vis–near IR spectroscopy characterization.
References (64)
- et al.
Invesigation on the Kinetic mechanism of of the reduction fo Fe2O3/CoO-decorated carbon xerogels: a non isothermal study
J. Solid State Chem.
(2019) - et al.
A detailed study on the dielectric properties of CCTO@SiO2 core-shell nanoparticles: role of SiO2-NH2 shell over CCTO core surface
J. Solid State Chem.
(2019) - et al.
Preparation, characterization and microwave absorbing properties of MoS2 and MoS2 -reduced graphene oxide (RGO) composites
J. Solid State Chem.
(2019) - et al.
High dielectric constant in ACu3Ti4O12 and ACu3Ti3FeO12 phases
J. Solid State Chem.
(2000) - et al.
Synthesis of bismuth titanate by the urea method
Mater. Lett.
(2005) - et al.
Synthesis and giant dielectric behavior of CaCu3Ti4O12 ceramics prepared by polymerized complex method
Mater. Chem. Phys.
(2008) - et al.
Dielectric and magnetic studies of 0.5Bi2/3Cu3Ti4O12- 0.5Bi3LaTi3O12 nano-composite ceramic synthesized by semi-wet route
Ceram. Int.
(2017) - et al.
Biodegradable polymer modified rGO/PANI/CCTO nanocomposites : structural and dielectric properties, Mater
Today Proc
(2018) - et al.
High permittivity and low dielectric loss of the Ca1-xSrxCu3Ti4O12 ceramics
J. Alloys Compd.
(2011) - et al.
Giant dielectric-permittivity property and relevant mechanism of Bi2/3Cu3Ti4O12 ceramics
Mater. Chem. Phys.
(2010)
Dielectric constant versus voltage and non-Ohmic characteristics of Bi2/3Cu3Ti4O12 ceramics prepared by different methods
Ceram. Int.
Effect of the synthesis route on the phase formation behavior and electric property of Na0.5Bi0.5Cu3Ti4O12 ceramics
Mater. Res. Bull.
Colossal dielectric permittivity and relevant mechanism of Bi2/3Cu3Ti4O12 ceramics
Ceram. Int.
Dielectric and magnetic studies of 0.5 Bi2/3Cu3Ti4O12 -0.5Bi3LaTi3O12 nano-composite ceramic synthesized by semi-wet route
Ceram. Int.
Characterization of Bi2/3Cu3Ti4O12 ceramics synthesized by semi-wet route
Prog. Nat. Sci. Mater. Int.
Na1/3Ca1/3Bi1/3Cu3Ti4O12: a new giant dielectric perovskite ceramic in ACu3Ti4O12 compounds
J. Eur. Ceram. Soc.
Structural, dielectric properties and electrical conduction behaviour of Dy substituted CaCu3Ti4O12 ceramics
Ceram. Int.
Combustion synthesis of nano-crystalline Bi2/3Cu3Ti2.90Fe0.10O12 using inexpensive TiO2 raw material and its dielectric characterization
Powder Technol.
Effect of semiconductive grain and microstructure on the dielectric properties of CaCu3Ti4O12 ceramics with Sr2+ doping
J. Alloys Compd.
Synthesis and characterizations of Nd3+ doped SrFe12O19 nanoparticles
Mater. Chem. Phys.
Synthesis, magnetic and dielectric properties of ErNi doped Sr-hexaferrite nanomaterials for applications in High density recording media and microwave devices
J. Magn. Magn Mater.
Structural properties of CaCu3Ti4O12 obtained by mechanical alloying
Mater. Sci. Eng. B Solid-State Mater. Adv. Technol.
Synthesis and giant dielectric behavior of CaCu3Ti4O12 ceramics prepared by polymerized complex method
Mater. Chem. Phys.
Mechanical synthesis and characterization of Bi4Ti3O12 nanopowders
Ceram. Int.
Nanoparticles of the giant dielectric material, calcium copper titanate from a sol-gel technique
Mater. Lett.
Effects of surface modification on interfacial and rheological properties of CCTO/PEN composite films
Colloids Surfaces A Physicochem. Eng. Asp.
Tuning the dielectric and optical properties of Pr-Co – substituted calcium copper titanate for electronics applications
J. Phys. Chem. Solid.
Electromagnetic interference (EMI) shielding , microwave absorption , and optical sensing properties of BaM/CCTO composites in Ku -band
Results Phys.
Sol-gel synthesis of mesoporous CaCu3Ti4O12 thin films and their gas sensing response
J. Solid State Chem.
Analysis of PV deposited ZnTe thin films through Urbach tail and photoluminescence spectroscopy
J. Lumin.
Effect of growth temperatures on the surface morphology, optical analysis , dielectric constants, electric susceptibility, Urbach and bandgap energy of sprayed NiO thin films
Opt. - Int. J. Light Electron Opt.
Cited by (17)
Improvement in the structural, magnetic and electromagnetic behaviour of barium hexaferrites with yttrium doping for EMI shielding
2024, Journal of Alloys and CompoundsCrystallographic dependence of the electrical transport mechanism in La-Mn-O thermosensitive thin films
2024, Journal of Alloys and CompoundsTuning the dielectric properties of PbNb<inf>2</inf>O<inf>6</inf> perovskite through calcium substitution
2022, Physica B: Condensed MatterCitation Excerpt :The peak height of these arcs decides the capacitance developed across the grain boundaries while diameter along the Zʹ axis determines the value of resistance [39]. These results are in good agreement with the measured σac in high frequency compass [40]. Moreover, no second semicircular arc is visible which points out that only single process contributes [16].