La_(1-x)Ca_xMnO_3低温高磁场下的电脉冲诱导电阻转变效应  

Electric Pulse Induced Resistive Switching of La_(1-x)Ca_xMnO_3 at High Magnetic Field and Low Temperature

作　　者：吴子华[1] 谢华清[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：《无机材料学报》2010年第9期961-965,共5页Journal of Inorganic Materials

基　　金：上海市优秀青年基金(EGD08012);上海高校特聘教授"东方学者"岗位计划~~

摘　　要：对La1-xCaxMnO3(x=0.3,0.5)多晶材料的巨磁电阻效应及低温高磁场下的电脉冲诱导电阻可逆变化(EPIR)效应进行了研究,并对两者之间的区别进行了分析.实验结果表明,La1-xCaxMnO3(x=0.3和0.5)多晶材料在低温高磁场下仍具有EPIR效应,电阻在相同电脉冲下的变化率不随温度和施加磁场与否发生变化,表现出不同于巨磁电阻效应的变化规律.结合之前的研究结果,发现巨磁电阻效应是由于磁场造成磁矩的有序并继而造成电子的退局域化引起的,而EPIR效应则是由于电脉冲诱导氧离子迁移,导致载流子浓度变化引起的.The colossal magnetoresistive and electric pulse induced resistive switching properties of La1-xCaxMnO3（x=0.3,0.5）polycrystalline at high magnetic field and low temperature were studied.The difference of colossal magnetoresistive and electric pulse induced resistive switching was analyzed.The EPIR effect of La1-xCaxMnO3（LCMO）（x=0.3,0.5）polycrystalline also exist at high magnetic field and low temperature.The ratio of high resistance state and low resistance state has no obviously change with varying temperature and magnetic field.The CMR property comes from double exchange and Jahn-Teller effect.Increasing the magnetization by applying an external field would increase the charge mobility of ferromagnetic phase and then decrease the resistance via the double exchange mechanism.Ions motion driven by electric pulses is presented for explaining the resistance switching.The motion of oxygen would change the hole density of local regions.The change of hole density would still exist at low temperature and modulate the low temperature magnetic configuration of LCMO.

关 键 词：CMR EPIR 氧离子迁移 La1-xCaxMnO3 

分 类 号：O484[理学—固体物理]