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 ano malous wide angle X-ray scattering study has been performed on a serie s of metallic glasses in order to relate their magnetic behaviour to t heir local and medium range order. Due to the large difference in size and electronic number, Z, between the three components, this techniqu e allows the determination of the surroundings of the cobalt and erbiu m atoms and the discrimination of the Go-Co, Er-Er and Co-Er correlati ons in the first coordination shell. A competition between the topolog ical disorder and a chemical ordering in the short and medium range oc curs when the Er content increases, which may influence their magnetic and thermodynamic properties.