Winkelmann Aimo, Przybylski Marek, Luo Feng, Shi Yisheng, Barthel Jochen
Max-Planck Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale), Germany.
Phys Rev Lett. 2006 Jun 30;96(25):257205. doi: 10.1103/PhysRevLett.96.257205. Epub 2006 Jun 29.
We grew tetragonally distorted FexCo1-x alloy films on Pd(001). Theoretical first-principles calculations for such films predicted a high saturation magnetization and a high uniaxial magnetic anisotropy energy for specific values of the lattice distortion c/a and the alloy composition x. The magnetic anisotropy was investigated using the magneto-optical Kerr effect. An out-of-plane easy axis of magnetization was observed for Fe0.5Co0.5 films in the thickness range of 4 to 14 monolayers. The magnetic anisotropy energy induced by the tetragonal distortion is estimated to be almost 2 orders of magnitude larger than the value for bulk FeCo alloys. Using LEED Kikuchi patterns, a change of the easy axis of magnetization can be related to a decrease of the tetragonal distortion with thickness.
我们在Pd(001)上生长了四方畸变的FexCo1-x合金薄膜。针对此类薄膜的理论第一性原理计算预测，对于晶格畸变c/a和合金成分x的特定值，会有高饱和磁化强度和高单轴磁各向异性能量。利用磁光克尔效应研究了磁各向异性。在4至14个单层的厚度范围内，观察到Fe0.5Co0.5薄膜存在垂直于平面的易磁化轴。由四方畸变引起的磁各向异性能量估计比块状FeCo合金的值大近2个数量级。利用低能电子衍射菊池花样，易磁化轴的变化可与四方畸变随厚度的减小相关联。
