纳米晶类钙钛矿型锰氧化物导电性的高压研究  

HIGH-PRESSURE STUDY OF CONDUCTIVITY PROPERTY OF NANOCRYSTALLINE PEROVSKITES-LIKE MANGANESE OXIDE 

作　　者：杨广亮[1] 鲜于文旭[1] 千正男[1] 金汉民[1] 

机构地区：[1]吉林大学物理系,长春130023

出　　处：《物理学报》2000年第3期553-556,共4页Acta Physica Sinica

基　　金：国家自然科学基金!(批准号 :196 740 16 )资助的课题

摘　　要：研究了纳米晶类钙钛矿型锰氧化物La0.7Sr0.3Mn0.95Fe0.05O3和La0.7Ca0.3MnO3在不同压力、高温处理后的导电性质.结果表明,在室温高压成型样品具有很高的电阻率,居里温度TC附近磁电阻效应很小;随处理压力的增加,电阻率先是降低,至11GPa时达最低点,之后升高.高温处理过的样品经一定压力处理后,其电阻随温度变化曲线的金属绝缘体转变峰向低温跃变,并伴随电阻率的大幅增加.The conductivity and magnetic properties of La 0.7 Sr 0.3 Mn 0.95 Fe 0.05 O 3 and La 0.7 Ca 0.3 MnO 3 nanocrystalline system prepared by high pressure and sintering method were investigated. The samples pressed under high-pressure at room temperature showed a huge resistivity and a small magnetoresistivity effect at the Curie temperature ( T C). With the increase of high pressure, the resistivity decreases, at \%P\%=1\^1GPa reaches a minimum, and then increases. After processing the samples by high pressure, which were first sintered at high temperature, the resistivty increases, and metal\|insulator transition shifts towards lower temperature.

关 键 词：纳米晶 类钙钛矿型 锰氧化物 导电性 高压 

分 类 号：O521[理学—高压高温物理]