An elementspecific investigation of the disorder induced phase transition in Fe60Al40 thin films driven by ion irradiation

Chemically ordered Fe60Al40 in the B2 structure presents a paramagnetic ordering, while the chemical disordered phase with the A2 structure exhibits a ferromagnetic state. This phase transition leads to a change of the effective number of nearest Fe neighbors [1] and of the lattice constant [2]. This phase transition can be driven by ion irradiation [3]. In this work we investigate Fe60Al40 thin films before and after 20 keV Ne+ irradiation by means of x-ray magnetic circular dichroism (XMCD) at the Fe L2,3- and K-edge to analyze the microscopic magnetic structure. For a comparison macroscopic magnetometry was used concerning the depth-profile of the induced magnetism [1]. These results are correlated to the modified structural properties.