The effects of vacuum annealing on the structural and transport properties of the La0.67Ca0.33MnO3−δ films grown on SrTiO3 (LCMO/STO) and NdGaO3 (LCMO/NGO) substrates have been studied. A lattice expansion due to oxygen release during the annealing is observed. Under the same condition, the change of the out-of-plane lattice parameter in LCMO/STO is two to three times larger than that in LCMO/NGO, indicating a strong tendency for the oxygen in the former to escape. Correspondingly, the metal-to-semiconductor transition shifts to lower temperatures, linearly with lattice constant until a critical value, Δd=0.03 Å for LCMO/STO and Δd=0.05 Å for LCMO/NGO, after which a sudden drop of the transition temperature to zero occurs. The different lattice strains in both films are presumably responsible for the different critical oxygen contents for the occurrence of the resistive transition.

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Thin copper films were grown on glass by pulsed-laser deposition. The simultaneous in situ monitoring of the electrical resistance and optical transmittance of the growing film yielded highly reproducible and consistent data about percolation onset and film conductivity, both being useful indicators of film quality. When prepared under favorable conditions, films as thin as 1.5 nm would percolate, and became fully continuous at 5 nm, with conductivity reaching 30% of that of bulk copper.