https://scholars.lib.ntu.edu.tw/handle/123456789/629804
標題: | Single-crystal epitaxial europium iron garnet films with strain-induced perpendicular magnetic anisotropy: Structural, strain, magnetic, and spin transport properties | 作者: | Guo, MX CHIA-KUEN CHENG Liu, YC Wu, CN Chen, WN Chen, TY Wu, CT CHIH-HUNG HSU Zhou, SQ Chang, CF Tjeng, LH Lee, SF Pai, CF Hong, M Kwo, J |
公開日期: | 2022 | 出版社: | AMER PHYSICAL SOC | 卷: | 6 | 期: | 5 | 來源出版物: | PHYSICAL REVIEW MATERIALS | 摘要: | Single-crystal europium iron garnet (EuIG) thin films were epitaxially grown on gadolinium gallium garnet (GGG)(001) substrates using off-axis sputtering and showed strain-induced perpendicular magnetic anisotropy (PMA). By varying the sputtering conditions, we have tuned the europium/iron (Eu/Fe) composition ratios in the films to tailor the film strains. The films exhibited an extremely smooth, particle-free surface with a root-mean-square roughness as low as 0.1 nm, as observed by atomic force microscopy. High-resolution x-ray diffraction analysis and reciprocal space maps showed pseudomorphic film growth, a very smooth film/substrate interface, excellent film crystallinity with a rocking curve of 0.012° (ω scans), and an in-plane compressive strain without relaxation. In addition, spherical aberration-corrected scanning transmission electron microscopy showed an atomically abrupt interface between the EuIG film and GGG. The saturation magnetization (Ms) and coercive field (Hc) were measured using a vibrating sample magnetometer. The square-shaped out-of-plane M-H loops in conjunction with angle-dependent x-ray magnetic dichroism demonstrated the PMA in the films. The spin Hall magnetoresistance on Pt/EuIG samples was measured to obtain the PMA field strength (H), which increases from 4.21 to 18.87 kOe with the increasing Eu/Fe ratio and in-plane compressive strain. We also measured spin transport in the Pt/EuIG bilayer structure and directly obtained the real part of spin mixing conductance to be 3.48×1014ω-1m-2. We demonstrated current-induced magnetization switching with a low critical switching current density of 3.5×106A/cm2, showing excellent potential for low-dissipation spintronic devices. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/629804 | ISSN: | 2475-9953 | DOI: | 10.1103/PhysRevMaterials.6.054412 |
顯示於: | 園藝暨景觀學系 |
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