The influence of substitutions on the magnetocaloric effect in RCo2 compounds

Abstract

Abstract We present a study of the magnetocaloric effect in selected substituted RCo2 compounds. The first system was Gd(Rh x Co1 – x )2 with x = 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30. The substitution of Co by Rh leads to a decrease in the critical temperature with increasing rhodium content from Tc = 350 K for x = 0.05 to T c = 200 K for x = 0.30. The maximum entropy change slowly increases with increasing Rh concentration and reaches about 1 J K– 1 kg– 1 for x = 0.30 and a field change of 1 T. The second studied system was Dy(Fe x Co1 – x )2 with x = 0.00, 0.01, and 0.03. The critical temperature as well as the magnetic entropy change strongly depends on the Fe concentration. The transition temperature increases from 140 K in DyCo2 to 210 K for 3 % Fe but the maximum of the entropy change quickly decreases from 5 to 1.2 J K–1 kg– 1 for field of 1 T.