Structural and electrical properties of c-axis oriented Y-Ca-Ba-Cu-Zn-O thin films grown by pulsed laser deposition

Ca- and Zn-subsituted Y1-xCaxBa2(Cu1-yZny)(3)O7-delta (x = 0, 0.05 and y = 0, 0.02, 0.04, 0.05) thin films were grown on SrTiO3 (100) substrates using the pulsed laser deposition (PLD) technique. Effects of various growth parameters on the quality of the film were studied via X-ray diffraction (XRD), atomic force microscopy (AFM), and in-plane resistivity, rho(ab)(T), measurements. The deposition temperature and oxygen partial pressure were gradually increased to 820 degreesC and 1.20 mbar, respectively. Films grown under these conditions exhibited good c-axis orientation (primarily limited by the grain size) and low values of the extrapolated residual resistivity, rho(0), at zero temperature. The planar hole content, p, was determined from the room-temperature thermopower, S[290 K], measurements and the effects of oxygen annealing were also studied. Fully oxygenated samples were found to be overdoped with p similar to 0.195. The superconducting transition temperature T-c(p), and rho(T,p) showed the expected systematic variations with changing Zn content. (C) 2004 Published by Elsevier B.V.