铁磁性锰氧化物掺杂的ZnO压敏电阻性能研究  

The study of ZnO varistor doped with ferromagnetic manganese oxide

作　　者：羊新胜[1] 赵勇[1] 

机构地区：[1]材料先进技术教育部重点实验室和超导研究开发中心,西南交通大学成都610031

出　　处：《物理学报》2008年第5期3188-3192,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50372052;50588201);国家重大基础研究项目(973)(批准号:2007616906)资助的课题~~

摘　　要：利用通常的电子陶瓷制备工艺制备了铁磁性锰氧化物La0.7Sr0.3MnO3掺杂的ZnO陶瓷.晶界处存在La0.7Sr0.3MnO3(LSMO)和LaMnO3(LMO)两种杂相.样品中绝缘相LMO的含量显著影响着样品的电学性能.掺杂后的样品仍具有一定的铁磁性.在样品上施加磁场后,样品电阻值增加,表现为正磁电阻性质.正磁电阻的出现,是由于磁场的存在增加了晶界处势垒的高度造成的.结果表明磁场可以改变多晶陶瓷样品中晶界处势垒的性质,从而改变样品的电输运特性.ZnO varistor doped with ferromagnetic manganese oxide （La0.7 Sr0.3 MnO3 ） was prepared by conventional electric ceramic technique. There are secondary phases, La0.7 Sr0.3 MnO3 and LaMnO3, existing at the grain boundaries. The content of insulating phase of LaMnO3 obviously affects the electrical properties of the samples. The samples still remained ferromagnetism after doping. Applied magnetic filed could change the electrical property. The resistance increased when magnetic field was applied, showing a positive magnetoresistance （PMR） phenomenon. The existence of PMR is due to the broadening of barrier at the grain boundaries caused by the magnetic field.

关 键 词：ZNO 压敏电阻 锰氧化物 正磁电阻 

分 类 号：O472[理学—半导体物理]