2025-09-17 東京科学大学
図1. 面内磁場によって制御される新しい異常ホール効果（上）。非磁性・反強磁性材料における場合（左下）と、今回の強磁性材料における場合（右下）。後者では磁場なしの状態においても軌道磁化が顕在化する。
＜関連情報＞
- https://www.isct.ac.jp/ja/news/3n2yol75y7x6
- https://www.isct.ac.jp/plugins/cms/component_download_file.php?type=2&pageId=&contentsId=1&contentsDataId=2257&prevId=&key=7445f6a0ac1218cc852aa6e85ed2a03b.pdf
- https://advanced.onlinelibrary.wiley.com/doi/10.1002/adma.202502624
強磁性酸化物における自発的面内異常ホール応答の観測 Spontaneous In-Plane Anomalous Hall Response Observed in a Ferromagnetic Oxide
Shinichi Nishihaya, Yuta Matsuki, Haruto Kaminakamura, Hiroki Sugeno, Ming-Chun Jiang, Yoshiya Murakami, Ryotaro Arita, Hiroaki Ishizuka, Masaki Uchida
Advanced Materials Published: 16 September 2025
DOI:https://doi.org/10.1002/adma.202502624
Abstract
Recent observation of anomalous Hall effect (AHE) induced by magnetic field or spin magnetization lying in the Hall deflection plane has sparked interest in diverse mechanisms for inducing the Hall vector component perpendicular to the applied magnetic field. Such off-diagonal coupling, which is strictly constrained by symmetry of the system, provides new degrees of freedom for engineering Hall responses. However, spontaneous response as extensively studied for out-of-plane AHE remains unexplored. Here, in-plane AHE in a typical ferromagnetic oxide SrRuO3 is elucidated. The (111)-orientated ultrathin films with in-plane easy axes of spin magnetization exhibit spontaneous AHE at zero field, which is intrinsically coupled to the in-plane spin magnetization and controllable via its direction. Systematic measurements by varying azimuthal and polar field angles further reveal complex Hall responses shaped by higher-order terms allowed by trigonal distortion of the films. These findings highlight versatile and controllable in-plane Hall responses with out-of-plane orbital ferromagnetism.
