Signatures of electronic phase separation in the Hall effect of anisotropically strained La0.67Ca0.33MnO3 films
Signatures of electronic phase separation in the Hall effect of anisotropically strained La0.67Ca0.33MnO3 films
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各向异性应变 La0.67Ca0.33MnO3 薄膜霍尔效应中电子相分离的特征
DOI：
10.1088/1367-2630/15/11/113057
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发表时间：
2013-11
影响因子：
3.3
通讯作者：
Liuqi Yu, Lingfei Wang, Xiaohang Zhang, W B Wu, S
中科院分区：
文献类型：
--
作者：
Liuqi Yu, Lingfei Wang, Xiaohang Zhang, W B Wu, S
对一系列具有不同程度的各向异性应变的 La0.67Ca0.33MnO3 薄膜进行了系统的输运测量。应变是通过 NdGaO3(001) 衬底上的外延生长引起的，并通过控制热退火时间来改变。热退火时会出现反铁磁绝缘（AFI）状态，可能与电荷排序有关。这些材料中的霍尔效应表现出的特征表明渗透相变，并与 AFI 状态的出现密切相关。在顺磁相中，所有样品中的霍尔电阻率都呈现两个斜率：在低场下，负斜率随着温度的升高而减小，这归因于载流子跳跃运动；在高场下，由于空穴的扩散传输，霍尔电阻率几乎与温度无关的正斜率。值得注意的是，不同温度下霍尔电阻率斜率的交叉场对应于相同的磁化强度，这被解释为磁场驱动的渗流相变的临界点。在接近零场金属-绝缘体转变的较低温度下，随着 AFI 状态的发展，观察到霍尔系数显着增强。增强峰值靠近磁场驱动的渗流；其大小与 AFI 态的强度相关，并且会因面内磁场 AFI 态的熔化而受到抑制。这些观察结果类似于成分驱动渗滤附近颗粒金属薄膜中霍尔系数增强的许多特征。
Systematic transport measurements have been performed on a series of La0.67Ca0.33MnO3 thin films with varying degrees of anisotropic strain. The strain is induced via epitaxial growth on NdGaO3(001) substrates and varied by controlling the thermal annealing time. An antiferromagnetic insulating (AFI) state, possibly associated with charge ordering, emerges upon thermal annealing. The Hall effect in these materials exhibits features that are indicative of a percolative phase transition and correlate closely with the emergence of the AFI state. In the paramagnetic phase, the Hall resistivity takes on two slopes in all samples: a decreasing negative slope with increasing temperature at low fields, which is attributed to the carrier hopping motion, and an almost temperature independent positive slope at high fields due to diffusive transport of holes. Significantly, the crossover fields of the Hall resistivity slope at different temperatures correspond to the same magnetization, which is interpreted as the critical point of a magnetic field-driven percolative phase transition. At lower temperatures near the zero-field metal–insulator transition, pronounced enhancement of the Hall coefficient with the development of the AFI state is observed. The enhancement peaks near the magnetic field-driven percolation; its magnitude correlates with the strength of the AFI state and is suppressed with the melting of the AFI state by an in-plane magnetic field. The observations resemble many features of the enhancement of the Hall coefficient in granular metal films near the composition-driven percolation.
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影响因子：
1.8
作者：
N. Mott
通讯作者：
N. Mott
影响因子：
3.7
作者：
Hong-Chang Yang;Li-Min Wang;H. Horng
通讯作者：
Hong-Chang Yang;Li-Min Wang;H. Horng
影响因子：
4
作者：
A. Pakhomov;X. Yan;B. Zhao
通讯作者：
A. Pakhomov;X. Yan;B. Zhao
DOI：
10.1080/00107517308210764
发表时间：
1973-09
期刊：
--
影响因子：
--
作者：
N. F. Mott
通讯作者：
N. F. Mott
影响因子：
3.7
作者：
C. Wan;P. Sheng
通讯作者：
C. Wan;P. Sheng