Structural and electrical characterisation of La0.5Ca0.5MnO3 thin films grown by pulsed laser deposition

Thin films of perovskite manganite, with nominal composition La0.5Ca0.5MnO3, have been prepared by pulsed laser deposition on (100) SrTiO3, (100) LaAlO3, (100) Si and YSZ/CeO2-buffered (100) Si substrates. Structural and electrical characterisation was performed on the films. The magneto-transport properties of all the thin films depart from the bulk behaviour. The LCMO film grown on buffered Si shows an insulator-metallic transition around 130-150 K while the one deposited directly on Si displayed a similar behaviour under a melting field of 1 T. However, that transition is absent in the films grown on LAO and STO. We suggest that appropriate stress values induced by the substrate favour the formation of metallic percolative paths. (C) 2002 Elsevier Science B.V. All rights reserved.