摘要
Bi_4Ti_3O_(12) is an important lead-free ferroelectric material.Doping modification of Bi_4Ti_3O_(12)has attracted great attention to improving its performances.In this work,the effect of Sr dopants on the microstructure,dielectric,and conductivity of Bi_4Ti_3O_(12) ceramic was investigated by XRD,SEM,and AC impedance spectroscopy.Substitution of 1 at%Sr for Bi decreased the grain size,suppressed the dielectric dispersion of Bi_4Ti_3O_(12) ceramic at room temperature,and resulted in different effects on the conductivity of grains and grain boundaries.The conductivity of grains in Bi_4Ti_3O_(12) ceramic was increased by the small amount of Sr dopants in the whole experimental temperature range.While the grain boundaries of 1 at%Sr-doped Bi_4Ti_3O_(12) exhibited lower conductivity than pure Bi_4Ti_3O_(12) below～380℃and higher conductivity above～380℃.The experimental phenomena were interpreted in term of compensating defects for Sr dopants.
Bi_4Ti_3O_(12) is an important lead-free ferroelectric material.Doping modification of Bi_4Ti_3O_(12)has attracted great attention to improving its performances.In this work,the effect of Sr dopants on the microstructure,dielectric,and conductivity of Bi_4Ti_3O_(12) ceramic was investigated by XRD,SEM,and AC impedance spectroscopy.Substitution of 1 at%Sr for Bi decreased the grain size,suppressed the dielectric dispersion of Bi_4Ti_3O_(12) ceramic at room temperature,and resulted in different effects on the conductivity of grains and grain boundaries.The conductivity of grains in Bi_4Ti_3O_(12) ceramic was increased by the small amount of Sr dopants in the whole experimental temperature range.While the grain boundaries of 1 at%Sr-doped Bi_4Ti_3O_(12) exhibited lower conductivity than pure Bi_4Ti_3O_(12) below～380℃and higher conductivity above～380℃.The experimental phenomena were interpreted in term of compensating defects for Sr dopants.
基金
supported by National Basic Research Program of China (No. 2016YFB0700502)
National Natural Science Foundation of China (No. 51372024)
