Anisotropic strains and magnetoresistance of La0.7Ca0.3MnO3
Anisotropic strains and magnetoresistance of La0.7Ca0.3MnO3
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DOI：
10.1063/1.119705
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发表时间：
1997-02
影响因子：
4
通讯作者：
T. Koo;S. Park;K. B. Lee;Y. Jeong
中科院分区：
文献类型：
--
作者：
T. Koo;S. Park;K. B. Lee;Y. Jeong
采用脉冲激光沉积法在SrTiO 3（100）、MgO（100）和LaAlO 3（100）衬底上外延生长了钙钛矿锰氧化物La 0. 7 Ca 0. 3 MnO 3薄膜。通过X射线衍射测量完全确定了这些薄膜样品以及大块样品的微观结构。三种膜的晶胞具有不同的形状，即，收缩的四方晶系，立方晶系，和拉长的四方晶系分别为SrTiO 3，MgO，和LaAlO 3，而体的晶胞是立方晶系。结果表明，立方晶胞样品在低场（~ 1 T）下的峰值磁阻小于非立方晶胞样品。结果表明，La0.7Ca0.3MnO3在低场下的磁电阻效应是由外加应变引起的晶格畸变控制的。
Thin films of perovskite manganite La0.7Ca0.3MnO3 were grown epitaxially on SrTiO3(100), MgO(100) and LaAlO3(100) substrates by the pulsed laser deposition method. Microscopic structures of these thin film samples as well as a bulk sample were fully determined by x-ray diffraction measurements. The unit cells of the three films have different shapes, i.e., contracted tetragonal, cubic, and elongated tetragonal for SrTiO3, MgO, and LaAlO3, respectively, while the unit cell of the bulk is cubic. It is found that the samples with a cubic unit cell show smaller peak magnetoresistance at low fields (≲1 T) than the noncubic ones do. The present result demonstrates that the magnetoresistance of La0.7Ca0.3MnO3 at low fields can be controlled by lattice distortion via externally imposed strains.