Spin reorientation and large magnetic anisotropy of metastable bcc Co islands on Au(001)
Spin reorientation and large magnetic anisotropy of metastable bcc Co islands on Au(001)
复制标题
DOI：
10.1103/physrevb.90.174410
复制
发表时间：
2014-11
影响因子：
3.7
通讯作者：
T. Miyamachi;T. Kawagoe;S. Imada;M. Tsunekawa;H. Fujiwara;M. Geshi;A. Sekiyama;K. Fukumoto;F. Chang;Hong‐ji Lin;F. Kronast;H. Dürr;C. Chen;S. Suga
中科院分区：
文献类型：
--
作者：
T. Miyamachi;T. Kawagoe;S. Imada;M. Tsunekawa;H. Fujiwara;M. Geshi;A. Sekiyama;K. Fukumoto;F. Chang;Hong‐ji Lin;F. Kronast;H. Dürr;C. Chen;S. Suga
我们通过X射线磁圆二色性结合扫描隧道显微镜和光电子发射显微镜研究了Au(001)上亚稳态bcc Co纳米结构的磁性和形貌。虽然室温下将 Co 沉积到 Au(001) 上会形成具有纯面内磁化强度的 bcc Co 薄膜，但这些薄膜在 500 K 下的后退火会极大地将形态改变为嵌入 Au 中的 bcc Co 岛。根据这种形态变化，我们发现额外出现了面外磁化，并且观察到岛面内和面外剩磁的共存。磁矩对纳米结构尺寸的依赖性表明，随着纳米结构尺寸的减小，岛的易磁化轴从面内方向变为面外方向。这种自旋重定向转变可能是由于在较小的岛屿中产生面外磁化的边缘原子分数增加所致。观察到的较小岛屿的面外剩余磁化强度表明它们具有较大的磁各向异性。
We studied magnetism and morphology of metastable bcc Co nanostructures on Au(001) by x-ray magnetic circular dichroism in combination with scanning tunneling microscopy and photoelectron emission microscopy. While room-temperature deposition of Co onto Au(001) leads to the formation of bcc Co thin films with pure in-plane magnetization, postannealing of these thin films at 500 K drastically changes the morphology to bcc Co islands embedded in Au. In accordance with this morphological change, we find that an out-of-plane magnetization emerges additionally and the coexistence of in-plane and out-of-plane remanent magnetizations is observed for the islands. The nanostructure-size dependence of magnetic moments suggests that the magnetization easy axis of the island changes from the in-plane to the out-of-plane direction with decreasing nanostructure size. Such a spin reorientation transition is likely due to the increased fractional population of rim atoms generating the out-of-plane magnetization in the smaller islands. The observed out-of-plane remanent magnetization of the smaller islands indicates their large magnetic anisotropy.