Stebliy Maksim E, Bazrov Michail A, Namsaraev Zhimba Zh, Letushev Michail E, Kozlov Aleksei G, Antonov Valerii A, Stebliy Ekaterina V, Davydenko Aleksandr V, Ognev Alexey V, Shiota Yoichi, Ono Teruo, Samardak Alexander S
Laboratory of Spin-Orbitronics, Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok 690950, Russia.
Sakhalin State University, Yuzhno-Sakhalinsk 693000, Russia.
ACS Appl Mater Interfaces. 2023 Aug 30;15(34):40792-40798. doi: 10.1021/acsami.3c08979. Epub 2023 Aug 18.
Nano- and microstructures based on ferrimagnets can demonstrate high efficiency and dynamics of current-induced magnetization switching combined with high stability of spin textures such as bubble domains and skyrmions, which are of practical importance for the development of spintronics and spin-orbitronics. This set of features is usually associated with magnetic momentum or angular momentum compensation states. Here, we experimentally show that the compensation state can be realized locally using nonuniform Joule heating. This effect is observed in the variable-width current guide made of the ferrimagnetic W/CoTb/Ru thin films, where the position of a region heated to the compensation temperature depends linearly on the current pulse amplitude. This approach makes it possible to observe the simultaneous coexistence of Co-dominant and Tb-dominant regions, where current pulses induce spin-orbit torques in opposite directions, leading to local magnetization switching. It is found that the position of a Néel domain wall constraining the switched region lies in the vicinity of the coordinate corresponding to the compensation point but does not coincide with it due to high mobility under the action of spin current. Our findings open an alternative approach for engineering of ferrimagnetic nanodevices with advanced properties for future applications in spintronics, spin-orbitronics, and nanoelectronics.
基于亚铁磁体的纳米和微观结构可以展现出电流诱导磁化翻转的高效率和动力学特性，同时具备诸如泡畴和斯格明子等自旋纹理的高稳定性，这对于自旋电子学和自旋轨道电子学的发展具有实际重要性。这一系列特性通常与磁矩或角动量补偿态相关。在此，我们通过实验表明，可以利用非均匀焦耳热在局部实现补偿态。在由亚铁磁W/CoTb/Ru薄膜制成的可变宽度电流导中观察到了这种效应，其中加热到补偿温度的区域位置与电流脉冲幅度呈线性关系。这种方法使得能够观察到Co主导区域和Tb主导区域的同时共存，在这些区域中电流脉冲会在相反方向上诱导自旋轨道转矩，从而导致局部磁化翻转。研究发现，限制开关区域的奈尔畴壁位置位于与补偿点对应的坐标附近，但由于在自旋电流作用下具有高迁移率，所以并不与之重合。我们的研究结果为设计具有先进特性的亚铁磁纳米器件开辟了一条替代途径，可用于自旋电子学、自旋轨道电子学和纳米电子学的未来应用。
