Thermal and spontaneous remagnetization in the bulk amorphous ferromagnets Nd60Fe30Al10 and Nd60Fe20Co10Al10

Abstract

Bulk amorphous Nd60Fe30Al10 and Nd60Fe20Co10Al10 alloys, which display hard magnetic properties, have been prepared by arc melting and quenching into a copper mould. Following magnetic saturation and dc demagnetization, at room temperature, both materials are seen to exhibit the phenomena of thermal and spontaneous remagnetizations. The behavior of the observed thermal and spontaneous remagnetizations is similar to that exhibited in nucleation controlled sintered permanent magnets. The thermal remagnetization data are fitted using a model, developed from the theory of Schumann and Jahn [J. Magn. Magn. Mater. 232, 231 (2001)] for explaining thermal remagnetization in polycrystalline magnets, to gauge its usefulness when applied to amorphous ferromagnets. The spontaneous remagnetization behavior is interpreted in the context of the Preisach model.