Dynamic phase separation as revealed by the strong resistance relaxation in epitaxially shear-strained La0.67Ca0.33MnO3/NdGaO3(0 0 1) thin-films
Dynamic phase separation as revealed by the strong resistance relaxation in epitaxially shear-strained La0.67Ca0.33MnO3/NdGaO3(0 0 1) thin-films
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DOI：
10.1016/j.jmmm.2010.07.003
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发表时间：
2010-11
影响因子：
2.7
通讯作者：
Zhen Huang;Guan-Yin GAO;Fuheng Zhang;Xianxian Feng;Ling Hu;Xiaoru Zhao;Yuping Sun;Wenbin Wu
中科院分区：
文献类型：
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作者：
Zhen Huang;Guan-Yin GAO;Fuheng Zhang;Xianxian Feng;Ling Hu;Xiaoru Zhao;Yuping Sun;Wenbin Wu
在10- 256 K的宽温度范围内，La_（0.67）Ca_（0.33）MnO_3/Nd_（001）薄膜中的铁磁金属和电荷有序绝缘体之间存在强烈的相竞争。基于各种磁输运测量，相边界的迁移率被推断为随温度而显著变化。在相界可移动的高温区，电阻率有较强的弛豫，而在低于40 K的冻结温度下，电阻率的弛豫减弱。在相分离（PS）背景下，温度或磁场驱动的相变会使双折射率趋于弛豫。此外，令人惊讶的是，虽然绝缘相的熔化场随膜厚度而变化，但是对于给定的膜，当开始时，它们保持不变，而不同的相分数由场或热循环产生。结果表明，在确定PS和这些外延薄膜中的相竞争的固有应变状态的至关重要的作用。
Strong phase competitions between the ferromagnetic metal and the charge-ordered-insulator have been induced in a wide temperature range of 10–256K for the shear-strained La0.67Ca0.33MnO3/NdGaO3(001) films. Based on various magnetotransport measurements, the mobility of phase boundaries was inferred to change dramatically with temperature. In the high temperature range where the phase boundaries are movable, strong relaxation in resistivity was observed, while at the frozen temperatures lower than 40K it is weakened. The resistivities tend to relax in accordance with the phase transitions driven by the temperature or magnetic field in the phase separation (PS) background. Moreover, to our surprise, while the melting fields of the insulating phase varied with film thicknesses, for a given film however, they stay unchanged when started with different phase fractions produced by the field or thermal cycling. The results show a crucial role of the inherent strain state in determining PS and phase competitions in these epitaxial thin films.