Magnetic properties of partially devitrified metallic glasses

This paper presents a review of selected experiments which have been carried out using partially devitrified Fe- and Co-based metallic glasses. It is shown that by a suitable choice of the starting metallic glass composition and of annealing conditions, a variety of magnetic phases can be created in these systems. It is also shown that by controlling annealing processes, the coercivity of metallic glass can be altered by several orders of magnitude, giving the possibility of tailoring materials with magnetic properties ranging from extremely soft up to semihard. The magnetostriction of nanocrystalline materials is discussed as well, showing that size-dependent phenomena and the symmetry restriction at the particle boundaries create a surface contribution to the effective magnetostriction. Finally, the magnetic interactions between particles in partially devitrified samples are considered and the observed influence of temperature and particle density on them is discussed.