Magnetocaloric effect in Er 15 Si 9 C

Abstract Magnetization ( M ) measurements were performed to study the magnetic properties and magnetocaloric effect in Er 15 Si 9 C crystallized in the hexagonal La 15 Ge 9 Fe-type structure with 4 non-equivalent Er sites. Er 15 Si 9 C ordered ferromagnetically at the Curie temperature ( T C ) of 33 K. At 5 K, M reached 4.5 μ B Er −1 , which is half of the saturation magnetization, arising from the crystalline electric field (CEF) effect. The slope of M(H) at 5 K decreased compared to that at 20 K, suggesting the antiferromagnetic interaction develops and a ferrimagnetic alignment exists due to the competition of magnetic interactions arising from the occupation of non-equivalent sites by Er atoms. The maximum values of the magnetic entropy change are 6 J K −1 kg −1 and 13 J K −1 kg −1 for magnetic field change of 2 T and 5 T, respectively. These values are relatively smaller than those of compounds with T C near 35 K, which originates from the CEF effect and the ferrimagnetism.