Effects of Co doping on the magnetic properties, entropy change, and magnetocaloric effect in Mn3Sn1-xCoxC1.1compounds

Abstract

The Mn3Sn1-xCoxC1.1 compounds are synthesized by a solid-state reaction method. The effects of Co doping on the magnetic properties, phase transition and entropy change are investigated in Mn3Sn1-xCoxC1.1 compounds. The Curie temperature first decreases from 283 K to 212 K (Mn3Sn0.9Co0.1C1.1) with increasing the Co concentration, and then increases to 332 K (Mn3Sn0.2Co0.8C1.1) with further increasing the Co concentration in Mn3Sn1-xCoxC1.1. The first-order transition of Mn3Sn1-xCoxC1.1 gradually changes into the second-order transition, in the mean time, the entropy change decreases and the phase transition region broadens from 9 K to 300 K with increasing the Co content. Both the magnetic entropy change and broadening the transition temperature span can influence the relative cooling power R. Finally we obtain the large R=103 J/kg (H=1.6 MA/m) in Mn3Sn0.8Co0.2C1.1, which could be used as the room-temperature magnetic refrigerant materials.