Critical indices in the magnetic ordering of iron–chromium–boron metallic glasses

We have measured the ac magnetic susceptibility and the dc magnetization as a function of field and temperature in a series of Fe8 0-xCrxB2 0 metallic glasses. Samples with x≤28 show ferromagnetic ordering which follows scaling law predictions, yielding well defined values of the critical indices δ and γ are quite similar for all samples, lying between 1.43 and 1.60, but values of δ increase from about 4 in the strongly ferromagnetic alloys to about 7 in the weakly ferromagnetic ones. Samples with 29≤x≤32 show a spin-glass-like phase, whose remanent magnetization exhibits characteristic time dependence.