Investigation of magnetic anisotropy and magnetic moments of tetragonal distorted Fe_(1-x)Co_x films on L1_0 FePt underlayer

摘要

Tetragonal distorted Fe_(1-x)Co_x (0 ≤ x ≤ 1) thin films are prepared on L1_0 ordered Fe_(0.6)Pt_(0.4) underlayer. The dependences of FeCo alloy composition on magnetic anisotropy energy (MAE) are investigated. Based on the LLG simulation, the tetragonal distorted Fe_(1-x)Co_x films show maximum positive magnetic anisotropy energy when the Co composition is around 60 at. %, while the MAE decreases and shifts to negative when the composition is close to pure Fe or Co. The experiment results prove that the MAE can be tuned by varying the alloy composition. Furthermore, the magnetic moments of Fe and Co in distorted Fe_(0.4)Co_(0.6) films are studied by the X-ray magnetic circular dichroism spectroscopy. The enhanced orbit moments which come from the lattice distortion increase the magnetic anisotropy energy of Fe_(0.4)Co_(0.6) film.