La_(0.7)Ca_(0.3)MnO_3多晶电致电阻效应与脉冲诱导电阻转变效应对比研究  

The Difference of CER and EPIR of LCMO Polycrystalline

作　　者：吴子华[1] 

机构地区：[1]上海第二工业大学城市建设与环境工程学院,上海201209

出　　处：《上海第二工业大学学报》2011年第1期40-44,共5页Journal of Shanghai Polytechnic University

基　　金：上海市教委优秀青年专项基金(No.RYQ308012)

摘　　要：对La0.7Ca0.3MnO3多晶的电致电阻效应(CER)和脉冲诱导电阻转变效应(EPIR)进行了对比研究。试验结果发现,EPIR效应可以由电脉冲诱导的氧离子迁移解释。氧离子的迁移引起Mn 4+/Mn 3+比率的变化并导致材料总的磁矩发生变化。而在CER效应中,外加的强直流电场使材料中形成大的铁磁性区域,当强电场消失后,较大的铁磁团簇区域将会保存下来,使总的磁化率升高。The influence of dc current flow on the resistivity and phase transition in doped La0.7Ca0.3MnO3 polycrystalline has been investigated.Application of high electric fields leads to the formation of ferromagnetic regions.The resistivity drops abruptly once the percolating current path is established.As current through the sample disappears,the larger FM clusters however remain and are frozen in giving a measurable contribution to the total magnetization and specific heat of the system.Ions motion driven by electric pulse current has been presented for explaining the effect of electric pulses induced resistance switching.The increase of oxygen ions would increase the ratio of Mn4＋/Mn3＋,which would decrease the total magnetic moment of La0.7Ca0.3MnO3.

关 键 词：LA0.7CA0.3MNO3 CER EPIR 磁矩 

分 类 号：O482.4[理学—固体物理]