Superconducting property of Zr–Co–Al–Nb metallic glasses

The superconducting property of Zr55Co(30−x)Al15Nbx (x = 0–20 at.%) metallic glasses fabricated by rapid solidification was investigated. The Zr55Co(30–x)Al15Nbx (x = 5–20 at.%) metallic glasses with a mixture structure of amorphous and nanocrystal phases exhibited superconductivity of Tc,on = 1.8–2.6 K. The maximum Tc,on = 2.6 K was obtained for the Zr55Co10Al15Nb20 metallic glass. This was attributable to the superconducting property of nanocrystalline particles contained in the Zr55Co10Al15Nb20 alloy. The increase of Nb element in the Zr55Co(30–x)Al15Nbx alloy led to the increase of Tc,on and the decrease of glass transition temperature. The glass transition temperature was between 704 and 749 K for the Zr55Co(30–x)Al15Nbx (x = 0–20 at.%) alloys. The temperature interval of supercooled liquid state was between 51 and 68 K for the Zr55Co(30–x)Al15Nbx (x = 0–20 at.%) alloys.