Magnetic properties and magnetocaloric effect in TbCo_2-xFe_x compounds

Magnetic properties and magnetocaloric effect in TbCo_2 - xFe_x compounds are studied by DC magnetic measurement. With increasing content of Fe, the entropy changes decrease slightly, though the Curie temperature is tuned from 231 K (x=0) to 303 K (x=0.1). Magnetic entropies of TbCo_2 compound are calculated by using mean field approximation (MFA). Results estimated by using Maxwell relation are consistent with that of MFA calculation. It is shown that the entropy changes are mainly derived from the magnetic entropy changes. The lattice has almost no contribution to the entropy change in the vicinity of phase transition.