NB DOPED SRTIO3 THIN-FILMS DEPOSITED BY PULSED-LASER ABLATION

Thin films of Nb doped SrTiOx (Nb-STO) have been fabricated on SrTiO3 (100) substrates by a pulsed laser deposition (PLD) technique and char acterized by XRD, AFM, XPS and electrical resistivity. It was found th at the preferred orientation of the deposited Nb-STO films was a-axis at a substrate temperature of 650 degrees C and oxygen pressures lower than 3 X 10(-1) Torr. The effect of the oxygen pressure on film prope rties such as surface roughness, lattice constants and chemical compos ition have been investigated. As the oxygen pressure was decreased, th e film surface morphology improved. Furthermore, the lattice constant of the a-axis increased with decreasing oxygen pressure, in spite of t here being no change in the Nb content detected in Nb-STO films. (C) 1 998 Elsevier Science S.A.