Huge magnetocrystalline anisotropy of x-ray linear dichroism observed on Co/FeMn bilayers

We present an x-ray spectromicroscopic investigation of single-crystalline magnetic FeMn/Co bilayers on Cu(001), using x-ray magnetic circular dichroism and x-ray magnetic linear dichroism (XMLD) at the Co and Fe L-3 absorption edges in combination with photoelectron emission microscopy. Using the magnetic coupling between the ferromagnetic Co layer and the antiferromagnetic FeMn layer, we are able to produce magnetic domains with two different crystallographic orientations of the magnetic easy axis within the same sample at the same time. We find a huge difference in the XMLD contrast between the two types of magnetic domains, which we discuss in terms of intrinsic magnetocrystalline anisotropy of XMLD of the Co layer. We also demonstrate that due to the high sensitivity of the method, the small number of induced ferromagnetic Fe moments at the FeMn-Co interface is sufficient to obtain magnetic contrast from XMLD in a metallic system.