Magnetization reversal and reorientation in DyCo5 systems

DyCo5 is a ferrimagnet which develops a compensation point (CP) at low temperatures where the magnetic structure switches 180 degrees, a spin reorientation (SR) point at a temperature higher then room temperature, where the magnetisation axis of Dy and Co drops in plane, parallel to the substrate. We present a systematic study of sputter deposited DyCo5 thin films using XMCD technique in a transmission geometry. The spin and orbital magnetic moments of Co and Dy exhibit a monotonous temperature dependence. The ferrimagnetic alignment between the Dy and Co moments is preserved across both phase transitions, occurring at the spin reorientation (TSR∝350 K) and at the compensation (TCP∝120 K) temperatures, respectively. Notably, the magnetic crystalline anisotropy changes orientation from in-plane at high temperatures to out-of-plane below TSR. At TCP the coercive field is strongly enhanced, diverging in size due to the reduced averaged magnetization specific to ferrimagnetic systems. Moreover, the orientation of the magnetic moments of Dy and Co reverses sign when crossing the TCP.