Pulsed laser deposition of superconducting Nb-doped strontium titanate thin films

We report on the growth of superconducting Nb-doped SrTiO3 thin films on LaAlO3 substrates by pulsed laser deposition. We find optimum Nb doping and high mobility for growth near 870 °C and chamber pressures below 3×10−4 Pa (2×10−6 Torr). The transport properties were measured from 300 K to 150 mK. The most highly doped samples display metallic behavior, and are superconducting below 350 mK, with transition temperatures similar to those of bulk single crystals.