The Large Magnetocaloric Effect in Amorphous Fe80-xMnxZr10 (x = 4,6,8,10) Alloys

The Magnetization behaviour has been measured for amorphous Fe_(90-x)Mn_xZr_(10) (x = 4,6,8,10) alloys. The Curie temperature decreased from 236 K to 195 K with increasing Mn concentration (x = 4 to x = 10). The magnetization measurements were conducted at temperatures above the Curie temperature in the paramagnetic region. In all samples, the magnetic properties showed superparamagnetic behavior above Tc where the mean magnetic moment of the superparamagnetic spin clusters decreased with increasing temperature. A large magnetic entropy change, ΔS_M, which is calculated from H vs M curves associated with the ferromagnetic-paramagnetic transitions in amorphous, has been observed. With Mn concentration increasing, ΔS_M decreases 1.04, 0.95, 0.87 J/㎏ K at 222, 210, 195 K (the Curie temperature), respectively.