弛豫型铁电体铌镁酸铅陶瓷的玻璃化行为研究  

GLASSY BEHAVIOR IN LEAD MAG-NESIUM NIOBATE RELAXORS

作　　者：程忠阳[1] 姚熹[1] 张良莹[1] 

机构地区：[1]西安交通大学电子材料与器件研究室,西安710049

出　　处：《物理学报》1996年第6期1026-1032,共7页Acta Physica Sinica

基　　金：国家自然科学基金资助的课题

摘　　要：钛酸铅与铌镁酸铅组成比为1:9的固溶体陶瓷是典型的弛豫型铁电体,其介电行为与偶极玻璃的介电行为极为相似,并已将玻璃学中的Vogel-Fulcher关系用于处理其介电常数峰值温度与频率的关系。本文测定了其介电行为随温度的变化,对其微观局域极化行为进行了分析,讨论了其局域极化的产生、增大及冻结过程,研究了弛豫型铁电体与Debye介质、玻璃体的关系和区别。在此基础上,提出了一个更合理的函数关系式,用以表征其介电常数峰值温度与频率的关系,并得出其介电弛豫激活能为0.037eV。实际应用表明,对于弛豫型铁电体,该函数关系较原有Vogel-Fulcher关系更有效。Evidence has been found that solid solution of 10 mol% lead titanate in lead magnesium niobate bears strong resemblance to spin and dipolar glasses. The frequency dispersion of the temperature of the permittivity maximum, Tm, has been analyzed using the Vogel-Fulcher relationship. The difference between the solid solution and glass was discussed. Based on this analysis, a new ralationship:ω = ω0exp {- (T0/Tm)p},was introduced which is more suitable and effective for relaxor ferroelectrics to analyze the frequency dispersion of the temperature of the permittivity maximum than Vogel-Fulcher relationship. The dielectric relation of the solid solution was measured The results were analyzed using the new relationship, and activation energy of 0.037 eV was obtaived.

关 键 词：铁电体 铌镁酸铅 陶瓷 玻璃化 

分 类 号：TM221[一般工业技术—材料科学与工程]