Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7920227 | Journal of Physics and Chemistry of Solids | 2018 | 37 Pages |
Abstract
Transition elements Nb, Mn and Zr were selected to substitute Ti of 0.4(Ba0.8Ca0.2)TiO3 -0.6Bi(Mg0.5Ti0.5)O3 (BCT-BMT) ceramic in order to extend its operation temperature and decrease its dielectric loss for the application of high-temperature capacitors. Nb and Mn play an opposite role on the defect compensation, decreasing and increasing the concentration of oxygen vacancies, respectively. The temperature of the maximum relative permittivity, Tm, decreases from 140â¯Â°C to 90â¯Â°C for the Nb and Zr modified BCT-BMT ceramics. The permittivity (εr) peak of the former exhibits a broad and stable relative permittivity â¼600 (±5% variation) from 50â¯Â°C to 520â¯Â°C with the dielectric loss â¤0.02 from 60â¯Â°C to 440â¯Â°C (1â¯kHz). The modified Curie-Weiss law indicates that the doping elements result in an enhancement of diffuse phase transition. Activation energies of relaxation frequency and conduction of the samples were characterized by the impedance spectroscopy. A clear relationship between the magnitude of activation energy and the concentration of oxygen vacancies was revealed.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Shaokai Ren, Zhi Chen, Tianxiang Yan, Feifei Han, Xiaojun Kuang, Liang Fang, Laijun Liu,