0.6(Na_(0.5)Bi_(0.5))TiO_3-0.4(Bi_(0.1)Sr_(0.9))TiO_3无铅压电陶瓷的铁电性和阻抗谱研究

Study on Ferroelectric Property and Impedance Spectroscopy of 0.6(Na_(0.5)Bi_(0.5))TiO_3-0.4(Bi_(0.1)Sr_(0.9))TiO_3 Lead-Free Piezoelectric Ceramics

采用传统固相法制备了0.6(Na_(0.5)Bi_(0.5))TiO_3-0.4(Bi_(0.1)Sr_(0.9))TiO_3陶瓷(即6BNT-4BST-9),研究了其相结构、铁电性能和储能特性;且利用复阻抗谱和电模量谱分析了其电性能。结果表明:(1)6BNT4BST-9陶瓷在室温时具有三方和四方共存的相结构;P-E回线和S-E曲线分析表明陶瓷中由非极性四方相占据主导。(2) 6BNT-4BST-9陶瓷具有较大Pmax～18.2μC/cm2,和较小的Pr～1.0μC/cm2;它在低场下的储能特性为W1=0.313 J/cm3,η=85.3%(@40kV/cm)。(3)M"-f和(-Z")-f曲线在同一位置的特征峰表明对于6BNT-4BST-9陶瓷只有一种材料微区对电性能起主导。6BNT-4BST-9陶瓷具有负温度系数的电阻-温度特性;根据Arrhenius Law计算的激活能Ea=1.48 eV,表明该陶瓷具有电子导电特征。

0.6(Na0.5Bi0.5)TiO3-0.4(Bi0.1Sr0.9)TiO3 (6BNT-4BST-9 for short) lead-free piezoelectric ceramics were fabricated by the traditional solid-state method, and the phase structure, ferroelectric property and energy-storage property of 6BNT-4BST-9 ceramics were investigated. Moreover, electrical properties of 6BNT-4BST-9 ceramics were studied by using the complex impedance spectra and complex modulus spectra. The results show that (1) 6BNT-4BST-9 ceramics exhibit coexistence phase structure of rhombohedral and tetragonal at room temperature. Non-polar tetragonal phase has a dominating position, which was identified by P-E loops and S-E curves.(2) 6BNT-4BST-9 ceramics show a large P max -18.2 μC/cm^2, a small P r-1.0 μC/cm^2, and low field energy-storage property with W 1=0.313 J/cm^3,η=85.3%(@40 kV/cm).(3) In M″-f and Z″-f curves, a peak was observed, indicating that only one materials micro structure plays a leading role in the electrical properties. 6BNT-4BST-9 ceramics show negative temperature coefficient of resistance behavior. The activation energy E a=1.48eV calculated from Arrhenius Law indicates that 6BNT-4BST-9 ceramics have the characteristics of electron conduction.