Synthesis and characterization of superconducting lead films by electroless plating on metallic and non-metallic substrates

Superconducting lead films have been synthesized using an electroless plating technique on a number of different substrates, including copper, silicon and sapphire. X-ray diffraction (XRD) measurements confirm that the films are lead with lead oxide impurities, and scanning electron microscope (SEM) images show that the films prepared on copper are uniform. However, samples deposited on silicon and sapphire exhibit pronounced structural irregularities. Temperature and magnetic field dependent magnetization measurements confirm that all three samples are superconducting with transition temperatures close to the value expected for bulk Pb. The Pb films deposited on a copper substrate have a superconducting volume fraction of approximately 45%, while the superconducting fraction for films on silicon and sapphire is on the order of 1%. We attribute this lower superconducting fraction to the presence of lead oxide impurities and structural defects in the samples.