Analysis of magnetization and magnetocaloric effect in amorphous FeZrMn ribbons

The magnetization behaviors have been measured for amorphous Fe90−xMnxZr10 (x=8 and 10) alloys. The Curie temperature is decreased from 210Kto185K with increasing Mn concentration (x=8 to x=10). The magnetization measurements were conducted at temperatures above the Curie temperature in the paramagnetic region. In both 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 ΔSM, which is calculated from H vs M curves associated with the ferromagnetic-paramagnetic transitions in amorphous, has been observed. The maximum ΔSM of Fe82Mn8Zr10 is 2.87J∕kgK at 210K for an applied field of 5T. The peak of magnetic entropy change was observed at the Curie temperature. The ΔSM decreases with increasing Mn concentration to 2.33J∕kgK.