Galstyan G. Structural and compositional changes induced by external influences in the surface layers of soft magnetic amorphous alloys

The physical nature of alterations in the structure and physical-chemical state of the surface and sub-surface region of amorphous ribbons of multicomponent Fe-В and Со-В based soft magnetic alloys induced by temperature, magnetic field and mechanical deformation effects has systematically been studied. The influence of temperature on the surface elemental and phase composition and electronic structure of a Finemet-type amorphous alloy was investigated in detail in a wide temperature range. It was found that heating the Finemet to a pre-crystallization temperature caused non-reversible processes of non-monotonic segregation of the alloy components, while cooling the alloy down to -155С and subsequent warming up gave rise to reversible changes in the surface elemental and phase composition. A mechanism of nanocrystallization of Finemet at the surface was suggested. The effect of low permanent magnetic field (В = 0.17 Т) on the surface composition, structure and mechanical characteristics of Finemet- and Metglas-type amorphous alloys was studied.