Effects of La~(3+) substitution on structure and temperature dependence of electrical properties of CaBi_4Ti_4O_(15)-Bi_4Ti_3O_(12) ceramics

摘要

Structure and temperature dependence of electrical properties of Ca(Bi,La)_4Ti_4O_(15)-(Bi,La)_4Ti_3O_(12) (CBT-BIT-xLa) ceramics were studied. With La~(3+) doping content increasing, the samples exhibited diffused dielectric constant anomalies, and the Curie temperature (T_c) decreased. Meanwhile, the dielectric loss of CBT-BIT-xLa was reduced. CBT-BIT-0.8La performed an improved piezoelectric constant (d_(33)) value of 23.4 pC/N and remained until the temperature increased to 500 ℃. In addition, CBT-BIT-0.8La performed an enhanced ρ_(dc) value of 3.26 × 10~(15) Ω cm, at room temperature. CBT-BIT-0.8La showed clearly higher dc resistivity (ρ_(dc)) than CBT-BIT, even with increasing the temperature to 600 ℃.