Magnetic phase transition and magnetocaloric effect in Mn5−xFexSi3

The magnetic phase transitions and the magnetocaloric properties of the pseudo binary system Mn5−xFexSi3 with x=0, 1, 2, 3, 4, 5 have been investigated by measuring the magnetisation as a function of temperature and magnetic field. With increasing Fe content, the antiferromagnetic ordering temperature shifts to higher temperatures. The compound Mn5Si3 is an antiferromagnet with a field-induced transition. At 4.2 K, the Mn5−xFexSi3 compounds with x=1 and 2 display antiferromagnetic behavior up to 38 T. For the compounds with x=4 and 5 we find ferromagnetic order. The magnetic-entropy changes in this system are derived from the temperature and field dependence of the magnetization by means of the thermodynamic Maxwell relation. For the MnFe4Si3 compound, enhanced but modest magnetic-entropy changes are observed. [Copyright &y& Elsevier]