Superconducting tunneling and upper critical field measurements of amorphous Zr based alloys

Abstract

Superconductivity has been studied in amorphous binary Zr (Ni, Mo, W) alloys. Zr 1− x Ni x shows a maximum critical temperature of 4.09 K at x=0.15. Tunelling experiments prove that amorphous ZrNi alloys are weak coupling superconductors. Amorphous Zr 1− x Mo x alloys were prepared from x=0.27 and x=0.40. Critical temperatures are around 4.2 K with no significant concentration dependence. X-ray diffraction shows a pronounced splitting of the second peak in the static structure factor S( q). In addition the isomorphous and isoelectronic amorphous alloy Zr 64W 36with T c=3.5 K could be prepared.