La_(0.85)Na_(0.15)MnO_3的结构、磁性质和输运性质  

STRUCTURE,MAGNETIC AND TRANSPORT PROPERTIES OF La_(0.85)Na_(0.15)MnO_3 CERAMICS

作　　者：李志青[1] 姜恩永[1] 刘新典[2] 任世伟[1] 白海力[1] 

机构地区：[1]天津大学理学院,天津300072 [2]河北工业大学应用物理系,天津300130

出　　处：《天津大学学报（自然科学与工程技术版）》2001年第5期681-683,共3页Journal of Tianjin University：Science and Technology

摘　　要：实验研究了由 Pechini方法制备的 L a0 .85Na0 .1 5Mn O3多晶陶瓷样品的结构、磁性质和输运性质 .发现 L a0 .85Na0 .1 5Mn O3的居里温度正好接近室温 ,在该温度附近 ,伴随铁磁相到顺磁相的转变 ,同时发生金属 -半导体转变 ,且在居里温度附近 ,0 .5 T外磁场下的最大磁电阻可达 14 % .理论与实验对比可知 ,在居里温度以上小极化子非对角跳跃为主要导电机制 .Polycrystalline La 0.85 Na 0.15 MnO 3 ceramics were prepared by Pechini process and their structure,magnetic and transport properties have been investigated.The Curie temperature,at which a transition from metallic to semiconducting occurs along with the transition from ferromagnetic to paramagnetic,is just in the vicinity of room temperature.In addition,a low field magnetoresistance about 14% at 0.5 T was observed near the Curie temperature.The small polaron hopping is considered to be the main transport mechanism above the Curie temperature by comparing the experimental data with the theoretical results.

关 键 词：磁电阻 双交换效应 金属-半导体转变 稀土锰氧化物 碱金属掺杂 结构 La0.85Na0.15MnO3 磁性质 输运性质 

分 类 号：O482.54[一般工业技术—材料科学与工程]