Structural, magnetic, and cryogenic magnetocaloric properties in the quaternary rare earths (RE) based RECr2Si2C (RE = Gd, Tb, Dy) compounds

Highlights: • The quaternary RECr₂Si₂C (RE = Gd, Tb, Dy) compounds are fabricated. • The structural, magnetic, MTP and MC properties in RECr₂Si₂C were studied. • The GdCr₂Si₂C compound is considerable for cryogenic magnetic refrigeration. -- Abstract: The rare earths (RE) based materials with large reversible magnetocaloric effects have been recently recognized as good candidates for practical cryogenic magnetic refrigeration. In this work, three RE-based quaternary silicon carbides of RECr₂Si₂C (RE = Gd, Tb, Dy) were synthesized and determined the crystal structure, magnetic properties, magnetic phase transition, and magnetocaloric performances. All RECr₂Si₂C compounds are crystallized in the carbon-filled CeMg₂Si₂-type crystal structure and revealed a second-order magnetic phase transition from ferromagnetic to paramagnetic without noticeable field or thermal hysteresis around the Curie temperatures (~10.9 K for GdCr₂Si₂C, ~16.6 K for TbCr₂Si₂C, and ~10.7 K for DyCr₂Si₂C). The magnetocaloric parameters including the maximum magnetic entropy change, temperature-averaged entropy changes with 3 K lift, as well as refrigerant capacity/relative cooling power are applied to determine the magnetocaloric performances, and the evaluated values are 21.7, 14.6 and 9.8 J/kgK, 20.97, 14.51, and 9.73 J/kgK, as well as 248.3/328.8, 302.8/393.8, and 211.3/274.9 J/kg for GdCr₂Si₂C, TbCr₂Si₂C, and DyCr₂Si₂C under the field change of 0–50 kOe. These results indicate that the GdCr₂Si₂C possesses promising magnetocaloric performances and is considerable for cryogenic magnetic refrigeration application.