First-order magnetic phase transition in FeRh-Pt thin films

The first-order antiferromagnetic/ferromagnetic phase transition in ordered FeRh100-XPtX (0 <= X <= 15) thin films grown onto MgO(100) substrate was investigated by temperature dependent magnetization measurements. It is shown that the phase transition temperature increases with increasing Pt content. The field dependence of transition temperature was also measured and a shift of -8 to -3.3 K/T is observed for FeRh100-XPtX thin films with increasing Pt contents. In addition, the entropy changes associated with the magnetic phase transition were studied, and it can be proposed that the change in electronic entropy associated with the magnetic moment of Rh atoms is the main mechanism for the first-order magnetic phase transition in ordered FeRh-based alloys. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3065973]