Structure and properties of transition-metal-metalloid glasses based on refractory metals

Abstract

The structure and properties of several new transition-metal-metalloid ($T_{1-x}{M}_x$) metallic glasses based on refractory transition metals (e.g., Mo, W, Ru, etc.) have been systematically investigated as a function of composition. The structure of the alloys has been investigated by x-ray diffraction methods and measurements of superconducting properties, electrical resistivity, density, hardness, and mechanical behavior were carried out. These data are used in developing a novel description of the structure of $T_{1-x}{M}_x$ glasses. The experimental evidence suggests that an ideal amorphous phase forms at a specific composition $x_c$ and that this phase has a well-defined atomic short-range order. For metallic glasses having $x<\mathrm{}{x}_c$ (metalloid poor glasses) "vacancylike" defects form, which are characterized by the excess volume which they contribute to the glass. Another, as yet unspecified defect appears to form in glasses with $x>\mathrm{}{x}_c$. This novel picture can explain the variation of many properties of these glasses with metalloid concentration.