Magnetic properties and magnetic domain structure of bulk glass forming Nd60Al10Fe20Co10 alloy

Abstract

The transition from hard to soft magnetic behaviour with increasing quenching rate is shown for Nd 60 Al 10 Fe 20 Co 10 melt-spun ribbons with different thickness. Microstructure and magnetic domain structure of ribbons were studied by magnetic force microscopy (MFM). Particle sizes < 5 nm decreasing gradually with increasing quenching rate were deduced from topographic images which differ from largescale magnetic domains with a periodicity of about 350 nm in all ribbons irrespective the coercivity. This indicates that the magnetic properties of the alloy are governed by interaction of small magnetic particles. It is concluded that the presence of short-range-ordered structures with a local ordering similar to the A1 metastable Nd -Fe binary phase is responsible for the hard magnetic properties in samples subjected to relatively low quenching rate.