Chen, K.; Lott, D.; Radu, F.; Choueikani, F.; Otero, E.; Ohresser, P.: Temperature-dependent magnetic properties of ferrimagnetic DyCo3 alloy films. Physical Review B 91 (2015), p. 024409/1-8
10.1103/PhysRevB.91.024409

Abstract:
Synchrotron soft x-ray magnetic circular and linear dichroism (XMCD and XMLD) spectroscopies at the Dy M4,5 and Co L2,3 edges are reported to investigate the temperature-dependent magnetic properties of rare earth–transition metal DyCo3 alloy films. In a temperature region between 4.4 K and 300 K, the two sites of Co and Dy are ferrimagnetic alloy coupled, with the Dy magnetization aligned to the applied field as the dominant site. The combined method of XMCD and XMLD and the application of the sum rules allows one to monitor the detailed changes in the magnetic contribution from both sites separately. It reveals that Dy possesses a very large moment of 8.2μB/atom at low temperatures. At higher temperatures, the reduction of the total magnetic moment is dominated by the behavior of the Dy magnetic moments which exhibit a steeper decrease, especially in the temperature regime between 150 K and 200 K. The reoccupation of the Zeeman split levels of the 4f sites of Dy indicates that thermal fluctuations are the driving force.