Superconducting properties of Be-Zr glassy alloys obtained by liquid quenching

Based on x-ray diffraction, electrical resistivity, critical field, glass transition, and density measurements, several superconducting properties of glassy ${\mathrm{Be}}_x{\mathrm{Zr}}_{100-x} \mathrm{}(30<x<\mathrm{}45\mathrm{})\mathrm{}$ alloys are studied. The transition temperature increases from about 1 K for $x=45\mathrm{} \mathrm{to} 2.8$ K for $x=30\mathrm{}$; this is attributed to the increase of the degree of disorder as Be concentration decreases. The glassy alloys are characterized as type-II medium-coupled superconductors with $\lambda =1\mathrm{} \mathrm{to} 1.5$ and with a high Ginzburg-Landau parameter of about 60.