La_(0.67)Ca_(0.33)MnO_3纳米多晶环的时效现象  

AGING OF RESISTANCE FOR NANOSTRUCTURED La_(0.67)Ca_(0.33)MnO_3

作　　者：王珂[1] 朱美红[1] 孙颖慧[1] 高绥宁[1] 张进[1] 邵春浩[1] 蔡伟[1] 赵永刚[1] 吴孝松[2] 吕力[2] 

机构地区：[1]清华大学物理系,北京100084 [2]中国科学院物理所,北京100080

出　　处：《低温物理学报》2006年第3期254-257,共4页Low Temperature Physical Letters

基　　金：国家自然科学基金(项目编号:50272031);国家973计划(项目编号:2002CB613505)资助的课题~~

摘　　要：利用脉冲激光沉积(PLD)方法在多孔Al2O3模板上制备了纳米结构La0.67Ca0.33MnO3(LCMO)多晶膜.温度为80K时,LCMO纳米多晶环样品的电阻随时间连续下降,表现出明显的时效特征.时效后,样品具有保持低电阻状态的性质.该时效行为可用扩展的指数函数拟合.通过拟合可以得到相应条件下的样品平衡态电阻、样品的特征驰豫时间等信息.利用Core-Shell模型以及自旋玻璃相的存在对观察到的时效行为及拟合结果进行了解释.We prepared Nanostructured La0.67 Ca0. 33 MnO3 （LCMO） films by pulsed-laser deposition （PLD） on porous Al2O3 substrates with an average thickness of 200nm. The temperature dependence of resistance was measured and the aging phenomenon of resistance was observed at 80K. The aging data can be well fitted using a stretched exponential function. From the fitted result, we can get the resistance corresponding to its stable state and the characteristic relaxation time at that temperature. The sample favors to keep the low resistance at that temperature after aging. Based on a Core-Shell model and the existence of spin-glass phase at the grain boundaries, we explained the observed resistance aging result and why our sample follows the stretched exponential law.

关 键 词：脉冲激光沉积 时效 Core-Shell模型 自旋玻璃 

分 类 号：TB383.1[一般工业技术—材料科学与工程]