DETERMINATION OF REVERSIBLE CURIE-POINT RELAXATION SPECTRA IN FE-B METALLIC GLASSES

Reversible Curie point (T(C)) and energy relaxation were investigated in Fe-B metallic glasses as a function of B content (x = 13.2 and 14.7 at%). The effect of the substitution of a small amount (5 at%) Fe by Ni on the energy relaxation of Fe86.8B13.4 Was also investigated. The calculation of the relaxation spectra of these alloys with relatively high T(C) values is not straightforward and it is made only possible by taking into account the exact annealing procedure. It is concluded that in Fe-B metallic glasses the relaxation spectrum of the Curie point decreases with the B content, together with that of the energy, indicating that boron inhibits the atomic movements during relaxation. This points to reversible topological atomic rearrangements (TSRO) as the source of relaxation in binary Fe-B alloys. The increase of the energy spectrum upon substitution of 5 at% Fe by Ni suggests that chemical ordering of metal atoms (CSRO) is the dominant process of the reversible relaxation in ternary Fe-Ni-B alloys.