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.