Magnetocrystalline anisotropy in FePd alloys studied using transverse X-ray magnetic circular dichroism

Abstract

The structural and magnetic properties of Fe 0.5Pd 0.5 alloys have been correlated using X-ray diffraction (XD), vibrating sample magnetometry (VSM) and transverse X-ray magnetic circular dichroism (TXMCD) at the Pd L 2,3 edges. XD indicates that codeposition of Fe and Pd, at elevated temperatures (350°C), results in a well-ordered L1 0 phase which exhibits perpendicular magnetic anisotropy (PMA). On the other hand, codeposition at room temperature results in a disordered phase with in-plane easy-axis of magnetization. By codepositing at intermediate temperatures, a series of alloys has been produced with varying degree of compositional order. The TXMCD results show that increased compositional ordering leads to an increased orbital moment anisotropy favouring PMA. The magnetocrystalline anisotropy energy resulting from the orbital anisotropy is compared to VSM results.