AN AWAXS STUDY OF CO-ER-B TERNARY AMORPHOUS METALLIC ALLOYS

Amorphous Co79x-yErxB21+y alloys, with x<10 at.% and y<3 at.%, belong to the series of ternary transition metal-rare earth-metalloid glasses of great interest for their high coercivity and magnetization. An anomalous wide angle X-ray scattering study has been performed on a series of metallic glasses in order to relate their magnetic behaviour to their local and medium range order. Due to the large difference in size and electronic number, Z, between the three components, this technique allows the determination of the surroundings of the cobalt and erbium atoms and the discrimination of the Go-Co, Er-Er and Co-Er correlations in the first coordination shell. A competition between the topological disorder and a chemical ordering in the short and medium range occurs when the Er content increases, which may influence their magnetic and thermodynamic properties.