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 210 K to 185 K 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 T, where the mean magnetic moment of the superparamagnetic spin clusters decreased with increasing temperature. A large magnetic entropy change Delta S-M, which is calculated from H vs M curves associated with the ferromagnetic-paramagnetic transitions in amorphous, has been observed. The maximum Delta S-M of Fe82Mn8Zr10 is 2.87 J/kg K at 210 K for an applied field of 5 T. The peak of magnetic entropy change was observed at the Curie temperature. The Delta Sm decreases with increasing Mn concentration to 2.33 J/kg K. (c) 2005 American Institute of Physics.