The superconducting properties of nanostructured Pb7Bi3 films obtained by pulse electroplating

► The Pb7Bi3 films were grown by pulse electroplating from organic and aqueous solution. ► The Pb7Bi3 film with the average grain size of 300nm showed Tc=7.8K. ► The Pb7Bi3 films with the nanocrystalline structure showed Tc=9–10.3K. ► The increase of Tc in Pb7Bi3 films is associated with their nanocrystalline structure. Nanocrystalline films of submicron thickness of the Pb–Bi alloy, including those of intermetallic compound Pb7Bi3, are obtained by means of pulsed current electroplating on the basis of complex-forming organic solvent, as well as of aqueous electrolyte basing on trilonate complex of lead and bismuth. The component (EDX) and phase (XRD) structure of films, the morphology of their surface are characterized. The dependence of electrical resistance of films from temperature and the temperatures of superconductivity state (Tc) are measured. The films with the average grain size of 300nm and Tc=7.8K are obtained with organic electrolyte containing lead and bismuth salts. Additional input of Ce3+ salt into the organic electrolyte allows obtaining films with Tc increased up to 10.3K. The films with the Tc risen up to 9.0 are also obtained by pulsed current electroplating from aqueous electrolyte. The increase of Tc in Pb7Bi3 films is associated with their nanocrystalline structure.