Electrical properties of AC3B4O12-type perovskite ceramics with different cation vacancies

• Published in: Materials research bulletin 2015-05, Vol.65, p.260-265
• Main Authors: Li, Guizhong, Chen, Zhi, Sun, Xiaojun, Liu, Laijun, Fang, Liang, Elouadi, Brahim
• Format: Article
• Language: English
• Subjects: Cation vacancy; Conductivity; Dielectric permittivity; Perovskite
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2015.02.012

[Display omitted] •AC3B4O12 perovskite with different concentration cation vacancies were prepared.•Cell parameter decreases with the increase of concentration of cation vacancies.•PTCO and CTO remain high dielectric permittivity but depress loss greatly.•Dielectric loss associates with cation vacancies and motion of oxygen vacancies. AC3B4O12-type perovskite CaCu3Ti4O12 (CCTO), □0.34Pr0.67Cu3Ti4O12 (PCTO), □1Cu3Ta2Ti2O12 (CTTO), □2Cu2Ta4O12 (CTO) ceramics with different concentration cation vacancies were prepared through traditional solid state reaction method. X-ray diffraction analysis indicated that CCTO and PCTO are perovskite cubic with space group Im-3 (no. 204) while CTTO and CTO are Pm-3 (no. 200). Cell parameter of the samples dramatically increases with the increase of cation vacancies. Dielectric permittivity of them maintains very high value of ∼104 from room temperature to 550K but the dielectric loss is depressed with the increase of cation vacancies in the same space group. The dielectric properties and conductivity behavior were described by the Debye relaxation and the universal dielectric response, respectively. The effect mechanism of cation vacancy and crystal structure on carrier transposition were discussed.