Competition between ferromagnetic metallic and paramagnetic insulating phases in manganites
Competition between ferromagnetic metallic and paramagnetic insulating phases in manganites
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DOI：
10.1063/1.1490153
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发表时间：
2002-08-01
影响因子：
3.2
通讯作者：
Wang, ZD
中科院分区：
文献类型：
--
作者：
Li, G;Zhou, HD;Wang, ZD
在(100)LaAlO_3衬底上生长了La0.67Ca0.33Mn1-xCuxO_3(x=0和0.15)外延薄膜，并用四探针法测量了其电阻率随温度的变化。我们发现铁磁金属(FM)和顺磁绝缘(PI)相之间的竞争在观察到的巨磁电阻(CMR)效应中起着重要的作用。基于掺杂锰氧化物近似由相分离的FM区和PI区组成的情况，提出了一个简单的唯象模型来描述CMR效应。利用该模型，我们计算了电阻率随温度和磁场的变化。该模型不仅定性地解释了与CMR效应有关的一些主要特征，而且定量地与实验观测结果相吻合。(C)2002年美国物理研究所。
La0.67Ca0.33Mn1-xCuxO3 (x=0 and 0.15) epitaxial thin films were grown on the (100) LaAlO3 substrates, and the temperature dependence of their resistivity was measured in magnetic fields up to 12 T by a four-probe technique. We found that the competition between the ferromagnetic metallic (FM) and paramagnetic insulating (PI) phases plays an important role in the observed colossal magnetoresistance (CMR) effect. Based on a scenario that the doped manganites approximately consist of phase-separated FM and PI regions, a simple phenomenological model was proposed to describe the CMR effect. Using this model, we calculated the resistivity as functions of temperature and magnetic field. The model not only qualitatively accounts for some main features related to the CMR effect, but also quantitatively agrees with the experimental observations. (C) 2002 American Institute of Physics.