锰对改善CaBi_4Ti_4O_(15)高温压电陶瓷性能的研究  

Electrical Properties of Mn-modified CaBi_4Ti_4O_(15) Piezoelectrics for High Temperature Application

作　　者：顾大国[1] 李国荣[1] 郑嘹赢[1] 曾江涛[1] 丁爱丽[1] 殷庆瑞[1] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《无机材料学报》2008年第3期626-630,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(50675218)

摘　　要：采用固相法制备了Mn改性的CaBi4Ti4O15（CBT＋xmol%MnCO3）层状压电陶瓷.介电温谱显示所有样品居里点在780℃附近,并且发现该材料在110K处有一介电弛豫峰.Mn的加入显著降低了高温下的介电损耗,剩余极化轻微降低,室温介电常数从173减小到162,同时机械品质因子由2700增加到4400,显示了硬性掺杂的效果.在100～600℃范围内,x=1.0的样品比纯组分的电阻率提高了一个数量级以上,500℃的电阻率提高了约2个数量级（10^8Ω·cm）,电阻率对温度的Arrhenius拟合由两段过渡到三段,压电系数d33由7提高到14.5.实验结果表明,Mn改性的CBT在高温传感器等领域具有应用前景.Mn-modified CaBi4Ti4O15 （CBT＋x mol% MnCO3） layer-structured piezoelectric ceramics were prepared by the solid state reaction technology. All samples have the same Curie temperature of 780℃, but the dielectric loss at high temperature is remarkably lowered by Mn addition. With increasing content of Mn, the remnant polarization is slightly decreased; the dielectric constant at room temperature decreases from 173 to 162; and the mechanical quality factor increases from 2700 to 4400. The piezoelectric constant d33 is enhanced from 7 to 14.5. The resistivity of 1.0mol% Mn modified sample is found to be 10^8Ω·cm at 500℃, 50 times higher than that of pure CBT. The Arrehenius plot of Mn-modified CBT is fitted by 3 straight lines, while that of pure CBT is fitted by 2 straight lines. The results suggest that the Mn modified CBT is a potential material for high temperature sensing application.

关 键 词：压电陶瓷 硬性掺杂 电阻率 CaBi4Ti4O15 

分 类 号：TM282[一般工业技术—材料科学与工程]