Pressure Effect on the Magnetic Transition Temperatures in the Intermetallic Compounds Mn₃MC (M=Ga, Zn and Sn)

Abstract

The pressure effect on the magnetic transition temperatures of Mn₃GaC, Mn₃ZnC and Mn₃SnC were measured under pressures up to 13 kbar. The pressure derivatives of the transition temperatures are obtained to be dT_t⁄dP=−3.5 K/kbar and dT_C⁄dP=0.4 K/kbar for Mn₃GaC, dT_t⁄dP=−0.9 K/kbar and T_C⁄dP=0 for Mn₃ZnC and dT_C⁄dP=−1.9 K/kbar for Mn₃SnC, where T_t and T_C are the magnetic order-order transition temperature and the Curie temperature, respectively. An intermediate magnetic phase (I) is induced in Mn₃GaC under pressures above 3 kbar. The triple point (Antiferro./I/Ferro.) was determined to be T_c=158 K and P_c=3 kbar. The temperature variations of magnetization, magnetic susceptibility and lattice parameter were also measured.