Strain-tuned magnetic anisotropy in sputtered thulium iron garnet ultrathin films and TIG/Au/TIG valve structures
Strain-tuned magnetic anisotropy in sputtered thulium iron garnet ultrathin films and TIG/Au/TIG valve structures
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DOI：
10.1063/1.5135012
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发表时间：
2020-02
影响因子：
3.2
通讯作者：
G. Vilela;H. Chi;G. Stephen;C. Settens;Preston Zhou;Y. Ou;D. Suri;D. Heiman;J. Moodera
中科院分区：
文献类型：
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作者：
G. Vilela;H. Chi;G. Stephen;C. Settens;Preston Zhou;Y. Ou;D. Suri;D. Heiman;J. Moodera
通过控制应变来定义亚铁磁绝缘体膜中的面内或面外易轴的磁各向异性，同时保持高质量的表面，对于自旋电子学和磁振子应用是期望的。我们研究的方法来调整非晶溅射的铥铁石榴石（TIG）薄膜的各向异性，从而定制其磁性能的厚度（7.5至60 nm），基板的选择（GGG和SGGG），和结晶过程。我们将形态和结构特性与生长后退火薄膜的磁各向异性相关联。在600 °C下退火的30 nm厚的膜显示出有利于面内磁各向异性（IPMA）的压缩应变，而在800 °C以上退火的膜处于导致垂直磁各向异性（PMA）的拉伸应变下。空气退火的薄膜呈现出高度的结晶度和接近体值的磁化饱和度。这些结果导致成功地制造三层TIG/Au/TIG，与TIG层之间的耦合取决于Au的厚度。这些结果将有助于使用TIG来创建各种原位清洁的混合结构的基本界面交换的研究，并朝着复杂的设备的发展。此外，溅射技术是有利的，因为它可以容易地按比例放大用于工业应用。
Defining the magnetic anisotropy for in-plane or out-of-plane easy axis in ferrimagnetic insulators films by controlling the strain, while maintaining high-quality surfaces, is desirable for spintronic and magnonic applications. We investigate ways to tune the anisotropy of amorphous sputtered ultrathin thulium iron garnet (TIG) films, and thus tailor their magnetic properties by the thickness (7.5 to 60 nm), substrate choice (GGG and SGGG), and crystallization process. We correlate morphological and structural properties with the magnetic anisotropy of post-growth annealed films. 30 nm thick films annealed at 600 °C show compressive strain favoring an in-plane magnetic anisotropy (IPMA), whereas films annealed above 800 °C are under a tensile strain leading to a perpendicular magnetic anisotropy (PMA). Air-annealed films present a high degree of crystallinity and magnetization saturation close to the bulk value. These results lead to successful fabrication of trilayers TIG/Au/TIG, with coupling between the TIG layers depending on Au thickness. These results will facilitate the use of TIG to create various in situ clean hybrid structures for fundamental interface exchange studies, and towards the development of complex devices. Moreover, the sputtering technique is advantageous as it can be easily scaled up for industrial applications.