Structural investigation of boron-containing metallic glasses

Structural investigations have been made of high boron-containing alloy glasses of compositions Co_100–x B _x withx=34, 36, 38 and 40 at % measured by X-ray diffraction. The characteristic second-peak splitting in the radial distribution function (RDF) is found for all samples presently investigated. The shoulders are also observed near the distances of 0.20 and 0.34 nm. The partial radial distribution functions of Co-Co and Co-B pairs have been derived from the measured total RDF data by applying the concentration method with the anomalous scattering technique, and the contributions from different atomic pairs to total RDF have been discussed. The calculation by the relaxed dense random packing model has been made for Fe-B alloy glasses with three different boron concentrations, i.e., 15, 25, and 40 at % boron and a comparison between the calculated and experimentally determined data is presented. The present model calculation could give the possible representation for the compositional dependence of the X-ray RDF for amorphous Fe-B alloys with boron contents of up to 40 at % as well as the different peak profile observed in the total RDF of X-ray data between Fe-B and Fe-P glasses.