Effect of thermophysical factors and magnetic field on the composition and optical properties of the surface of ribbons of amorphous cobalt- and iron-based alloys

Abstract

Ellipsometric measurements of the surface of ribbons of amorphous Co₅₉Fe₅Ni₁₀Si₁₁B₁₅ and Fe₆₁Co₂₀Si₅B₁₄ alloys before and after thermal and laser treatments and Auger analysis of their surface layers have been performed in order to determine the character of changes in the composition of these layers after the noted treatments. It is found that magnetostriction significantly affects the processes of modification of the atomic structure of the surface layer of ribbons of amorphous iron-or cobalt-based alloys and formation of a microrelief of their surface from the noncontacting side after cryogenic treatments under the same conditions. Specifically, magnetostriction is characteristic of amorphous iron-based alloys and is responsible for the optical anisotropy induced in the skin layer. It is established that annealing of ribbons of a Co-based amorphous alloy, even at the temperature T = 425°C, changes the character of the spectral dependence of the IR optical conductivity of this alloy to that described by the Drude relation. This change fixes the beginning of ordering of the atomic structure of the surface layer of the material with the formation of microscopic crystallization regions.