Mollick Safiul Alam, Singh Ranveer, Kumar Mohit, Bhattacharyya Satyaranjan, Som Tapobrata
SUNAG Laboratory, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India.
Nanotechnology. 2018 Mar 23;29(12):125302. doi: 10.1088/1361-6528/aaaa74.
We present a systematic investigation on uniaxial magnetic anisotropy (UMA) in Co thin films induced by high aspect ratio nanopatterned anisotropic substrates. Self-organized long grating-like nanostructures, with extreme regularities, are fabricated on Ge surfaces using Au-ion implantation at room temperature. Subsequently deposition of Co films are carried out on the same at two different angles. Magneto-optical Kerr effect measurements show strong UMA in Co films grown on ion-patterned Ge substrates, fabricated under different ion fluences, along and perpendicular to the direction of the patterns (long grating-like nanostructures). Magnetic force microscopy measurements under different externally applied magnetic fields reveal an easy domain wall motion when the field is applied along the grating-like nanostructures. On the other hand, high amplitude grating-like nanostructures hinder the spin rotation when the field is applied along the hard axis. The present study will be useful for magnetic recording media and ultra-small magnetic field sensors.
我们对由高纵横比纳米图案化各向异性衬底诱导的钴薄膜中的单轴磁各向异性（UMA）进行了系统研究。在室温下使用金离子注入在锗表面制备了具有极高规则性的自组织长光栅状纳米结构。随后，在相同表面以两个不同角度进行钴膜的沉积。磁光克尔效应测量表明，在不同离子注量下制备的、沿和垂直于图案（长光栅状纳米结构）方向生长在离子图案化锗衬底上的钴膜中存在强单轴磁各向异性。在不同外部施加磁场下的磁力显微镜测量表明，当磁场沿光栅状纳米结构施加时，畴壁易于移动。另一方面，当磁场沿硬轴施加时，高振幅光栅状纳米结构会阻碍自旋旋转。本研究将对磁记录介质和超小型磁场传感器有用。
