Ab initio calculations of Curie temperatures in GdX compounds

We present calculations of Curie temperatures of selected GdX (X = Zn, Rh, Mg, Cd) compounds with a cubic CsCl structure. Exchange interactions are obtained from ab initio electronic structure calculations in the framework of density functional theory. Critical temperatures are evaluated using two approaches, namely the mean-field approximation (MFA) and a more involved, random phase approximation (RPA). Calculated critical temperatures serve as theoretical upper estimate (MFA) and lower estimate (RPA) of an exact critical temperature given by the Heisenberg model. Obtained results are in fair agreement with experimental values.