Magnetocaloric effect of mononitride containing gadolinium and dysprosium Gd xDy 1− xN

Abstract

The binary rare-earth mononitride, Gd x Dy 1− x N, was synthesized by carbothermic reduction performed in a nitrogen gas stream. A continuous solid solution with the NaCl structure was observed through the whole composition range, and the Curie temperature was found to vary from 61 to 21 K as x changes from 1 to 0. The magnetocaloric effect was evaluated as a function of x by calculating the magnetic entropy changes Δ S from the magnetization data sets measured at various temperatures and applied fields. The Δ S values of Gd x Dy 1− x N expressed in terms of J K −1 m −3 were comparable to those of intermetallic compounds of rare earth and transition metals previously reported. Gd x Dy 1− x N is a promising magnetic refrigerant for hydrogen liquefying system because rare earth nitrides would not react with hydrogen.