类钙钛矿化合物(La_(0.8-x)Ce_xSr_(0.2))_(0.97)MnO_3的电磁性能研究  

Transport and Magnetic Properties of Perovskite-Type Manganite (La_(0.8-x)Ce_x Sr_(0.2))_(0.97)MnO_3

作　　者：余江应[1] 张世远[2] 

机构地区：[1]安徽建筑工业学院数理系,安徽合肥230022 [2]南京大学物理系固体微结构国家重点实验室,江苏南京210093

出　　处：《中国稀土学报》2005年第5期613-616,共4页Journal of the Chinese Society of Rare Earths

基　　金：国家重点基础研究发展规划资助项目(G1999064508)

摘　　要：探索性地研究了由内含不同程度CeO2的廉价原料———La2O3制备的,名义成分为(La0.8-xCexSr0.2)0.97MnO3(x=0~0.26)类钙钛矿锰氧化物的相结构、电磁性能,及其作为固体氧化物燃料电池(SOFC)空气极材料的可能性。实验显示,样品中除了磁性的钙钛矿相外,均出现了非磁性的Mn3O4相和不同程度的CeO2相;随着制备样品的原材料La2O3纯度的不同,样品的电阻率、磁电阻比等电磁特性也随之发生明显的变化;样品在1 T磁场下的室温磁电阻比的范围可达-3%^-14%;对x=0,0.037,0.26的样品,其电导率在600 K以上高温区均表现出较好的温度稳定性,表明其作为SOFC空气极材料的可行性。Phase structures, the transport and magnetic properties of the Perovskite-type manganite （La0.8-x CexSr0.2）0.97 MnO3 （x = 0 - 0.26） prepared by La2O3 with different contents of CeO2 were studied. Experiments show that the compounds consist of a magnetic perovskite phase and non-magnetic CeO2 and Mn3O4. The resistivity and magnetoresistance ratio （MR） of the samples vary with changing x. Their room-temperature MR reaches - 3% ～ - 14% at the magnetic field of 1 T. For x = 0; x = 0.037 and x = 0.26 sampies, the conductance keeps unchanged basically in a relatively wide temperature range above 600 K, and the result shows that it is feasible for producing SOFC cathode materials with these samples.

关 键 词：固体氧化物燃料电池(SOFC) 类钙钛矿锰氧化物 庞磁电阻(CMR) 磁电阻比 稀土 

分 类 号：TM271.2[一般工业技术—材料科学与工程]