The magnetization behavior and magnetocaloric effect in amorphous Fe–Nb–B ribbons

The magnetization behavior and magnetic caloric effect have been analyzed for amorphous Fe93−xNb7Bx (numbers indicate at.%; x = 9, 14, 20) alloys. An amorphous phase was formed after quenching by melt spinning with a copper wheel surface speed of 30 m/s. The magnetization measurements of the samples were performed by vibrating sample magnetometer. The Curie temperature increased from 299 to 419 K with increasing B concentration (x = 9–20). Temperature dependence of the entropy change, ΔSM was calculated from the isothermal magnetization. The values of ΔSM are 1.44, 1.07 and 0.97 J/kg K at x = 9, 14 and 20, respectively. The maximum of ΔSM was found to appear in the vicinity of the Curie temperature in these alloy samples.