Quantitative imaging of hybrid chiral spin textures in magnetic multilayer systems by Lorentz microscopy
Quantitative imaging of hybrid chiral spin textures in magnetic multilayer systems by Lorentz microscopy
复制标题
DOI：
10.1103/physrevb.100.214431
复制
发表时间：
2019-12-24
影响因子：
3.7
通讯作者：
Reyren, N.
中科院分区：
文献类型：
--
作者：
Fallon, K.;McVitie, S.;Reyren, N.
具有界面Dzyaloshinskiii-Moriya相互作用的垂直磁化多层膜中的手征磁性织构是近年来研究的热点。与破坏的反转对称性之间的界面处的铁磁层和重金属与大的自旋轨道耦合的手征支持纯手性尼尔域壁和刺猬（尼尔）skyrmions。根据自旋轨道扭矩这些尼尔型磁性结构的预测，并已被测量，以高速移动。然而，最近的研究表明，一些多层系统可能具有更复杂的混合畴壁配置，由于界面的极化和层间偶极场之间的竞争。这些扭曲的纹理，预计有厚度依赖尼尔和布洛赫贡献域或skyrmion壁。在这项工作中，我们使用洛伦兹显微镜的方法来定量实验确定（i）的贡献的尼尔和布洛赫组件和（ii）他们的空间自旋变化在高分辨率。这些与建模和模拟的结构，与我们的实验结果非常吻合。我们的定量分析提供了有力的直接证据的布洛赫壁组件，存在于这些混合墙，将是显着的手征性时，利用自旋电子应用。
Chiral magnetic textures in ultrathin perpendicularly magnetized multilayer film stacks with an interfacial Dzyaloshinskii-Moriya interaction have been the focus of much research recently. The chirality associated with the broken inversion symmetry at the interface between an ultrathin ferromagnetic layer and a heavy metal with large spin-orbit coupling supports homochiral Neel domain walls and hedgehog (Neel) skyrmions. Under spin-orbit torques these Neel-type magnetic structures are predicted, and have been measured, to move at high velocities. However recent studies have indicated that some multilayered systems may possess a more complex hybrid domain wall configuration, due to the competition between interfacial DMI and interlayer dipolar fields. These twisted textures are expected to have thickness dependent Neel and Bloch contributions to the domain or skyrmion walls. In this work, we use the methods of Lorentz microscopy to determine quantitatively experimentally both (i) the contributions of the Neel and Bloch components and (ii) their spatial spin variation at high resolution. These are compared with modeled and simulated structures that are in excellent agreement with our experimental results. Our quantitative analysis provides powerful direct evidence of the Bloch wall component which exists in these hybrid walls and will be significant when exploiting chirality in spintronic applications.