Epitaxial La0.35Nd0.35Sr0.3MnO3 (LNSMO) films and SrTiO3 (STO)/LNSMO heterostructures have been grown on LaAlO3 substrates by pulsed laser deposition. The effect of oxygen content on structure and properties of both the LNSMO and STO/LNSMO films was investigated through x-ray diffraction, atomic force microscopy, and resistivity-temperature measurements. It is found that the out-of-plane lattice constant and the metallic-semiconducting transition temperature of the LNSMO films are greatly influenced by the oxygen pressure during deposition, but, insensitive to the in sial annealing oxygen pressure ranging from 2X10(-6) to 10 Torr after the deposition. For the STO/LNSMO heterostructures, oxygen out-diffusion from the LNSMO layer is evidenced when the top STO is deposited at an oxygen pressure of less than 5 X 10(-4) Torr and temperatures higher than 500 degrees C. Our results strongly suggest that at the surface of as-grown LNSMO films a native passivation layer for oxygen diffusion may exist, and this layer could be damaged after depositing the STO film at reduced oxygen pressures.
|Number of pages||6|
|Journal||Journal of vacuum science & technology. A, Vacuum, surfaces, and films|
|Publication status||Published - 2000|
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Condensed Matter Physics
- Surfaces and Interfaces