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 b y taking into account the exact annealing procedure. It is concluded t hat in Fe-B metallic glasses the relaxation spectrum of the Curie poin t decreases with the B content, together with that of the energy, indi cating that boron inhibits the atomic movements during relaxation. Thi s points to reversible topological atomic rearrangements (TSRO) as the source of relaxation in binary Fe-B alloys. The increase of the energ y spectrum upon substitution of 5 at% Fe by Ni suggests that chemical ordering of metal atoms (CSRO) is the dominant process of the reversib le relaxation in ternary Fe-Ni-B alloys.