Structural, magnetic and magnetocaloric properties of Ni43Mn46-xFexSn11 (x = 0, 6, 8, 10) alloys

The structural, magnetic and magnetocaloric properties of Ni43Mn46-xFexSn11 alloys prepared using arc melting and annealing have been investigated. The room temperature x-ray diffraction patterns show that the cubic austenite phase is the main phase in these alloys. The annealed Ni43Mn46-xFexSn11 alloys, except Ni43Mn36Fe10Sn11, show magneto-structural phase transitions, where the transition temperature systematically decreases with the increase in Fe concentration. The Ni43Mn36Fe10Sn11 alloy shows a second-order phase transition from a ferromagnetic to a paramagnetic phase at its Curie temperature. The peak magnetic entropy change and the relative cooling power of the Ni43Mn36Fe10Sn11 alloy measured at 30 kOe are about 2.0 Jkg-1K-1 and 130 Jkg-1, respectively. The absence of magnetic and thermal hysteresis coupled with relatively high cooling efficiency suggests that the Ni43Mn36Fe10Sn11 alloy has potential for magnetic refrigeration.