烧结温度对0.525Bi0.5Na0.5TiO3-0.475Ba0.85Ca0.15TiO3陶瓷电性能的影响

Effect of Sintering Temperature on Electrical Properties of 0.525Bi0.5Na0.5TiO3-0.475Ba0.85Ca0.15TiO3 Ceramics

采用溶胶-凝胶法制备了0.525Bi0.5Na0.5TiO3-0.475Ba0.85Ca0.15TiO3粉体(0.525BNT-0.475BCT),采用DSC-TGA、XRD、介电测试系统和铁电测试系统研究了0.525BNT-0.475BCT干凝胶的的分解性能,及不同烧结温度对0.525BNT-0.475BCT陶瓷相变及介电、铁电性能的影响。研究结果表明:0.525BNT-0.475BCT干凝胶粉在600℃以上达到完全分解,当烧结温度在1190℃时,开始出现准同相界,最大介电常数εr=3940,最优铁电性能(Pr=1.7μc/cm2,Ec=678v/mm)。表明溶胶-凝胶法制备的0.525BNT-0.475BCT陶瓷性能优异,是一种有前景的压电材料。

0.525Bi0.5Na0.5TiO3-0.475Ba0.85Ca0.15TiO3 powder (0.525BNT-0.475BCT) was prepared by sol-gel method. The decomposition properties of 0.525BNT-0.475BCT xerogels were studied by DSC-TGA. The effects of sintering temperature on the phase transformation, dielectric and ferroelectric properties of 0.525BNT-0.475BCT ceramics were also investigated by XRD, dielectric testing system and ferroelectric test system. The results show that the 0.525BNT-0.475BCT xerogel powder can be completely decomposed at above 600 ℃. When the sintering temperature is 1190 ℃, the morphotropic phase boundary appears and the maximum dielectric constant εr=3940, and the optimum ferroelectric properties (Pr=1.7 μc/cm2, Ec=678 v/mm). It indicates that the 0.525BNT-0.475BCT ceramics prepared by sol-gel method are excellent in performance and are promising piezoelectric materials.