Three first order magnetic phase transitions in re-entrant ferromagnet PrMn1.4Fe0.6Ge2

Three first order magnetic phase transitions (FOMTs) have been detected and evaluated over the temperature range from 5 to 340 K at fields up to 9 T in PrMn1.4Fe0.6Ge2. All three FOMTs, from (with decreasing temperature) an antiferromagnetic (AFl) to a c-axis canted ferromagnetic (Fmc) state, to a c-axis canted antiferromagnetic (AFmc) state, and then to an Fmc state plus an additional Pr-sublattice magnetic contribution (Fmc + F(Pr)), exhibited temperature and field-induced transition features. A interesting phenomenon was observed, in that magnetic field can induce an AFmc to Fmc + F(Pr) transition, and then diminish and finally eliminate the re-entrant magnetic transition behavior under high field as well. Based on systematic measurements and analysis, a magnetic phase diagram has been determined.