| La0.67Ca0.33MnO3薄膜中的非欧姆行为研究 |
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| 引用本文： | 张春霞,虞澜,张鹏翔.La0.67Ca0.33MnO3薄膜中的非欧姆行为研究[J].云南大学学报(自然科学版),2004,26(5):417-420. |
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| 作者姓名： | 张春霞 虞澜 张鹏翔 |
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| 作者单位： | 昆明理工大学,光电子新材料研究所,云南,昆明,650051 |
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| 基金项目： | 国家自然科学基金资助项目(10274026). |
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| 摘 要： | 用四探针法对不同倾斜衬底La0.67Ca0.33MnO3薄膜进行了不同电流下的电阻温度关系测试,发现了3个结果:①偏电流>1mA时,焦耳热作用使电阻温度曲线的转变点温度下降;②偏电流<1mA时,薄膜的转变点电阻随所加的偏电流的增加而减小,这是对欧姆行为的偏离(即非欧姆行为);③这一偏离随衬底倾斜角度的增加而增加.对经过氧气氛高温退火的La0.67Ca0.33MnO3薄膜进行了测量,发现峰值电阻及峰值电阻的变化明显减小.初步分析的结果是:①大电流的加热效应是峰值温度偏移;②可能是晶界作为隧穿结导致了薄膜中的非欧姆行为.
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| 关 键 词： | 非欧姆行为 超巨磁电阻 LCMO薄膜 |
| 文章编号： | 0258-7971(2004)05-0417-04 |
| 修稿时间： | 2003年12月23 |
Nonohmic behavior in La0.67Ca0.33MnO3 films |
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| ZHANG Chun-xia,YU Lang,ZHANG Peng-xiang.Nonohmic behavior in La0.67Ca0.33MnO3 films[J].Journal of Yunnan University(Natural Sciences),2004,26(5):417-420. |
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| Authors: | ZHANG Chun-xia YU Lang ZHANG Peng-xiang |
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| Institution: | Institute of Advanced Materials for Photo-electronics, Kunming University of Science and Technolegy, Kunming 650051, China |
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| Abstract: | In this experiment,La0.67Ca0.33MnO3 films grown on different canted LaAlO3 substrates were tested with different bias currents.The results found are:① the temperature of the peak resistance decreases obviously due to the Joule heat effect when the current is lager than 1mA;② the maximum resistance in R-T curves is reduced with the current increasing when the current is less than 1mA.This is a deviation from the Ohm’s law(namely nonohmic behavior);③ the nonohmic behavior become larger with the canted angle increasing.By analyzing,two results were obtained:① Joule heat effect causes the transit temperature TM-I to decrease;② nonohm behavior in films is possibly caused by the grain boundries as tunneling resistance junctions. |
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| Keywords: | nonohm behavior colossal magnetoresistance LCMO film |
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