Magnetisation dynamics of as quenched and pulse annealed soft metallic glasses

Abstract

Pulse annealing method (PAM) is a practical and effective method to improve the magnetic characteristics of metallic glasses. Pulse annealing method overcomes oxidation problems during the annealing process. It minimises the difficulties in managing the crystallisation steps and causes low coercivity in contrast to high susceptibility in milliseconds. In this work, Fe77Cr2Si5B16 and Fe39Ni39Mo4Si6B12 metallic glasses were annealed by PAM. The ferromagnetic resonance spectra were measured, and the angular variation of resonance fields at the out of plane geometries was studied. The effective magnetisation and g factor fitting parameters were obtained as 3450 and 3750 Oe for Fe77Cr2Si5B16 and Fe39Ni39Mo4Si6B12 respectively from the angular variation of the resonance field. The M-H loops at room temperature were also plotted, and the changes of the magnetic properties were observed after pulse annealing. Amorphous to nanostructure steps can be seen from this method without any doubt.