Depth-resolved magnetic structure across the ferromagnetic to helical-antiferromagnetic phase transition in Dy/W(110)

We investigated the magnetic depth profile during the transition from the ferromagnetic (FM) to the helical-antiferromagnetic (AFM) phase in Dy-metal films grown on W(110). To this purpose, we used the strongly varying photon penetration depth across the Dy M-5 absorption threshold in resonant magnetic soft x-ray diffraction. Unlike in earlier studies on Dy films with two equivalent interfaces, we find a gradual growth of the AFM part of the film with temperature. The near-surface magnetic structure does not become FM and appears to serve as seed layer for the growth of the AFM order.