搜索

x
中国物理学会期刊

Pt/La0.67Sr0.33MnO3异质结中的反常霍尔效应

CSTR: 32037.14.aps.72.20221852

Anomalous Hall effect in Pt/La0.67Sr0.33MnO3 heterojunctions

CSTR: 32037.14.aps.72.20221852
PDF
HTML
导出引用
  • 非磁/铁磁异质结构中存在很多有趣的演生现象, 特别是, 铂/铁磁异质结构中的反常霍尔效应是一个研究热点. 采用脉冲激光沉积技术和射频磁控溅射技术制备出具有原子级接触界面的铂/锰酸锶镧异质结, 并对异质结的电输运性能进行了系统的研究. 实验发现, 铂/锰酸锶镧异质结中存在由铂贡献的反常霍尔效应, 这是由磁近邻效应诱导铂表现出铁磁性造成的. 反常霍尔电阻随着温度的降低而急剧增加, 并且在低于 40 K时改变符号. 反常霍尔电阻随铂厚度的增加而急剧降低, 证实了铂的铁磁性起源于异质结界面. 此外, 异质结在低外加磁场下可能产生了拓扑霍尔效应, 这是由异质结界面处的Dzyaloshinskii-Moriya相互作用诱导产生手性磁畴壁结构引起的. 上述研究结果为进一步理解非磁/铁磁异质结构中的电子自旋和电荷输运之间的相互作用提供了实验基础.

     

    Many emergent and novel phenomena occur in nonmagnetic/ferromagnet heterostructures. In particular, Pt/ferromagnet heterostructures where the Pt has strong spin-orbit coupling and thus can convert spin current into charge current, has attracted a great attention recently. The anomalous Hall effect (AHE) has been found in many Pt/ferromagnet heterostructures. However, the underlying physics remains elusive, so it is necessary to find more heterostructures in order to provide more experimental data. In this work, we investigate anomalous Hall resistances (AHRs) in Pt thin films sputtered on epitaxial La0.67Sr0.33MnO3 (LSMO) ferromagnetic films. High-quality Pt/LSMO heterojunctions are fabricated by pulsed laser deposition and RF-magnetron sputtering. The physical properties of LSMO films are characterized by the measurements of magnetic and transport properties. The AHR mainly contributed by Pt in the Pt/LSMO heterojunction increases sharply with temperature decreasing and changes its sign below 40 K. Furthermore, the AHR decreases sharply with the increase of Pt thickness. Those facts suggest that the ferromagnetism of Pt originates from interface due to magnetic proximity effect. Interestingly, this heterojunction can exhibit possible signal of topological Hall effect under low applied magnetic field. The above results provide an experimental basis for further understanding the interactions between electron spin and charge transport in nonmagnetic/ferromagnetic heterostructures.

     

    目录

    /

    返回文章
    返回