Magnetocaloric effect in LaMn2−xFexGe2 at near room temperature

LaMn2−xFexGe2 (x=0.10x=0.10, 0.15, 0.20) alloys were prepared by arc-melt method, the crystal structure and magnetic properties have been investigated by XRD and vibrating sample magnetometer, respectively. The arc-melted LaMn2−xFexGe2 alloys mainly crystallize in LaMn2Ge2 phase with ThCr2Si2-type tetragonal structure, the Curie temperature declines gradually from 310.7 K at x=0.10x=0.10 to 274.5 K at x=0.20x=0.20 with the increase of transition metal Fe content. The magnetic entropy changes of the series alloys, with the field change from 0 to 18 kOe, are obtained based on the magnetization isotherms at different temperature. The maximal magnetic entropy of LaMn2−xFexGe2 decreases a little with increasing substitution of Fe for Mn and is about 1.02 J/(kg K) (0–18 kOe) at x=0.10x=0.10.