MAGNETOCALORIC EFFECT IN AMORPHOUS AND NANOCRYSTALLINE FeCrNbBCu ALLOYS

The magnetocaloric effect in series of amorphous and nanocrystalline Fe(73.5)Cr(5)Nb(4.5)B(16)Cu and Fe(72)Cr(8)Nb(3)B(16)Cu samples has been studied by evaluating the magnetic entropy changes, Delta S(m), from magnetization data. An addition of different amount of chromium to the FeNbBCu and the subsequent heat treatment were used to shift the Curie temperature of amorphous phase, T(C)(am), to the vicinity of room temperature. Upon a 0.6 T magnetic field change, the maximum entropy change Delta S(m) similar to 0.5 J/kgK is found at the Curie temperature T(C)(am) approximate to 310K of the amorphous Fe(72)Cr(8)Nb(3)B(16)Cu alloy. Hence, the FeCrNbBCu alloys could be considered as potential low cost magnetic refrigerants near room temperature.