Structures, magnetic properties, and magnetocaloric effect in MnCo1−xGe (0.02⩽x⩽0.2) compounds

The crystalline structures, magnetic properties and magnetocaloric effect (MCE) of MnCo1−xGe alloys (0.02⩽x⩽0.2) have been reported. The crystalline structures of MnCo1−xGe (x⩽0.06) alloys are mainly of TiNiSi-type phase, and Ni2In-type structure dominates for x>0.06. With decreasing Co concentrations the saturated magnetization of these compounds decreases. Large low-field magnetic entropy change −ΔSM of about 2.3 J/kg K in MnCo0.94Ge alloy has been obtained for a magnetic field change of 1 T. Moreover, it is found that TiNiSi-type phase exhibits larger −ΔSM than Ni2In-type one. For MnCo0.94Ge alloy, considerable low-field refrigerant capacity (RC) (∼460 mJ/cm3), low coercivity and easy synthesis make these alloys potential candidates for near-room temperature magnetic refrigerants.