Large low-field magnetocaloric performances of the ErCu1.95T0.05Si2 (T = Mn, Fe, Co and Ni) compounds

Abstract

Magnetocaloric materials are at the heart of magnetic refrigeration (MR) technology. However, there is a scarcity of materials with a large magnetocaloric effect (MCE) at magnetic fields below 2 T. To address this limitation, we investigate the effect of doping in the ErCu2Si2 compound with relatively inexpensive neighboring atoms of Mn, Fe, Co, and Ni in the Cu position, respectively. The results show a significant enhancement in the MCE at low fields. Under the magnetic field change of 0–2 T, the values of maximum magnetic entropy change (−ΔSMmax) for the ErCu1.95T0.05Si2 (T = Mn, Fe, Co and Ni) compounds are 16.4 J/kg·K, 17.5 J/kg·K, 17.8 J/kg·K, and 18.6 J/kg·K, respectively. Compared to those of the parent compound ErCu2Si2, the −ΔSMmax of the ErCu1.95T0.05Si2 (T = Mn, Fe, Co and Ni) compounds exhibit enhancements of 3%, 11%, 13%, and 17%, respectively. Additionally, the magnetic transition temperatures of these doped compounds are lower than that of the parent compound ErCu2Si2, occurring below 2 K. Therefore, ErCu1.95T0.05Si2 (T = Mn, Fe, Co and Ni) compounds with large low-field MCE and negligible loss of hysteresis have the potential to serve as candidate materials for cryogenic magnetic refrigeration.