Sign reversal of planar Hall effect with temperature in La-doped Sr2IrO4 films
Sign reversal of planar Hall effect with temperature in La-doped Sr2IrO4 films
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DOI：
10.1063/5.0134002
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发表时间：
2023-01
影响因子：
4
通讯作者：
Mingrui Liu;Jianing Yue;J. Meng;T. Shao;C. Yao;Xiaojuan Sun;J. Nie;Dabing Li
中科院分区：
文献类型：
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作者：
Mingrui Liu;Jianing Yue;J. Meng;T. Shao;C. Yao;Xiaojuan Sun;J. Nie;Dabing Li
电子掺杂的Sr2IrO4是非常规超导电性的最佳候选者，但超导电性的直接证据尚未得到实验证实。因此，探索掺杂引起的复杂而丰富的物理性质是当务之急。平面霍尔效应是表征磁性薄膜内禀磁性的一种灵敏技术，在自旋电子学器件中有着广泛的应用。在这项工作中，La掺杂Sr2 IrO 4薄膜的PHE与磁场方向和温度的函数关系表现出由电子掺杂引起的独特性质。PHE的振幅与所施加磁场的强度成比例。值得注意的是，随着温度的升高，在90 K时，随角度变化的PHE发生了符号反转，这表明磁各向异性发生了变化。随后的变温传统霍尔测量和时间分辨光学研究消除了不同类型的载流子相互作用。各向异性磁电阻的测量表明，符号反转可以归因于电子掺杂后自旋结构的变化，反转温度与铁磁性的强度有关。这些结果提供了一个平台，以研究磁相互作用，并建议在电子掺杂Sr2IrO4薄膜中实现热可控磁传感器器件的可能性。
Electron-doped Sr2IrO4 is the best candidate for unconventional superconductivity, but direct evidence of superconductivity has not been experimentally confirmed. Therefore, it is urgent to explore the complex and rich physical properties caused by doping. The planar Hall effect (PHE) is a sensitive technique for the characterization of intrinsic magnetic properties in magnetic thin films and is applied widely in spintronic devices. In this work, the PHE for La-doped Sr2IrO4 films as a function of the magnetic field direction and temperature exhibited unique properties caused by electron doping. The amplitude of PHE is proportional to the strength of the applied magnetic field. Remarkably, as the temperature increased, a sign reversal of angle-dependent PHE occurred at 90 K, which indicated the change of magnetic anisotropy. Subsequent variable-temperature traditional Hall measurements and time-resolved optical studies eliminated different types of carrier interactions. The anisotropic magnetoresistance measurements indicated that the sign reversal can be attributed to the changes of a spin structure after electron doping, and the reversal temperature is related to the strength of ferromagnetism. These results provide a platform to study the magnetic interactions and suggest the possibility of realizing thermal controllable magnetic sensor devices in electron-doped Sr2IrO4 films.