物理学报2013，Vol.62Issue(2)：476-482,7.DOI:10.7498/aps.62.026201
Pr0.7Ca0.3MnO3陶瓷晶界势垒的交流特性
AC properties of Pr0.7Ca0.3MnO3 ceramics
摘要
Abstract
Ceramic Pr1_xCaxMnO3 (x = 0.3) samples are prepared by solid-state reaction and measured using direct current (DC) and alternating current (AC) methods in different magnetic and electrical fields. A Curie temperature of 150 K is determined by Ⅰ-Ⅴ measurements in field for Pr0.7Ca0.3MnO3, which is consistent with that from vibrating sample magnetometer (VSM). The AC measurement shows that the grain boundary resistance reduces with magnetic field increasing, while the grain almost keeps unchanged, and it indicates that the colossal magnetoresistance (CMR) effect in low field mainly comes from the grain boundary for the Pr0.7Ca0.3MnO3 ceramic. The barrier height of grain boundary is 117 meV for the Pr0.7Ca0.3MnO3 ceramic, obtained by fitting the temperature spectrum of impedance, and it is well coincident with that from fitting the R-T data. A "trap state" model is proposed to explain all the measured data.关键词
钙钛矿结构锰氧化物/庞磁电阻(CMR)/肖特基势垒/空间电荷层Key words
perovskite manganite oxide/ colossal magnetoresistance (CMR)/ Schottky barrier/ space charge region引用本文复制引用
石大为,吴美玲,杨昌平,任春林,肖海波,王开鹰..Pr0.7Ca0.3MnO3陶瓷晶界势垒的交流特性[J].物理学报,2013,62(2):476-482,7.基金项目
国家自然科学基金(批准号:11074067,11174073)资助的课题. （批准号:11074067,11174073）
