Perpendicular magnetic anisotropy properties of tetragonal Mn3Ga films under various deposition conditions
Perpendicular magnetic anisotropy properties of tetragonal Mn3Ga films under various deposition conditions
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DOI：
10.1016/j.cap.2015.10.012
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发表时间：
2016-01-01
影响因子：
2.4
通讯作者：
Jung, Myung-Hwa
中科院分区：
文献类型：
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作者：
Bang, Hyun-Woo;Yoo, Woosuk;Jung, Myung-Hwa
结果表明，四相Mn 3Ga薄膜具有高的垂直磁各向异性、低的饱和磁化强度和高的自旋极化率，满足自旋转移矩器件的要求.对于实际的器件应用，有必要改善界面性质和优化沉积条件。采用DC/RF磁控溅射方法，在MgO（100）衬底上直接制备了四相Mn 3Ga薄膜。我们研究了不同沉积条件下的结晶度、微结构和磁性能;例如沉积温度（350 - 450摄氏度）、RF功率（25-40 W）和Ar气体压力（2-7 mTorr）。X射线衍射数据显示生长方向垂直于膜平面，即，C轴。扫描电子显微镜图像显示，顶表面是平坦的，最大厚度为290 nm。在我们的溅射系统中，最佳沉积条件为400摄氏度、35 W和5 mTorr。对于垂直于薄膜平面的磁场，在室温下观察到明显的磁滞回线，饱和磁化强度为M-S - 100 emu/cc。通过外推平行于膜平面的磁场的硬磁化数据，估计各向异性能量约为K-1 = 1 × 10（6）J/m（3）。(C)2015爱思唯尔B. V.保留所有权利。
The tetragonal Mn3Ga films exhibited high perpendicular magnetic anisotropy, low saturation magnetization, and high spin polarization, which satisfy the criteria of spin-transfer-torque based devices. For practical device applications, it is necessary to improve the interface nature and optimize the deposition conditions. We fabricated thin films of tetragonal Mn3Ga directly on MgO(100) without any buffer layer by using DC/RF magnetron sputtering method. We investigated the crystallinity, microstructure, and magnetic properties with varying the deposition conditions; such as deposition temperature (350 -450 degrees C), RF power (25-40 W), and Ar gas pressure (2-7 mTorr). X-ray diffraction data revealed that the growth direction is perpendicular to the film plane, i.e., the c axis. Scanning electron microscope images showed that the top surface is flat with a maximum thickness of 290 nm. The optimal deposition conditions are 400 degrees C, 35 W, and 5 mTorr in our sputtering system. For the field perpendicular to the film plane, clear hysteresis loop was observed with the saturation magnetization M-S - 100 emu/cc at room temperature. By extrapolating the hard magnetization data for the field parallel to the film plane, the anisotropic energy was estimated about K-1 = 1 x 10(6) J/m(3). (C) 2015 Elsevier B.V. All rights reserved.