Dielectric and pyroelectric studies on the Ba_(1-3a)Bi_(2a)TiO_3 classical and relaxor ferroelectric ceramics

摘要

Low frequency dielectric studies in the temperature range 80-500 K were performed on the solid solution derived from BaTiO_3, Ba_(1-3a)Bi_(2a)TiO_3 with 0 < a < 0.117. The temperature and frequency variations of the real part of the relative permittivity show two different behaviors, depending upon the substitution rate. A classical ferroelectric behavior was observed for a varying approximately from 0 to 0.03. However, a relaxor behavior appears for higher values of a. The replacement of Ba~(2+) by Bi~(3+) in the A site shows a remarkable decrease of T_C. The dielectric studies were confirmed by pyroelectric study.