Abstract
epitaxial films with La:Al cation ratios ranging from 0.9 to 1.2 were grown on -terminated (001) substrates by off-axis pulsed laser deposition. Although all films are epitaxial, rocking curve measurements show that the crystallographic quality degrades with increasing La:Al ratio. Films with La:Al ratios of 0.9, 1.0, and 1.1 were coherently strained to the substrate. However, the out-of-plane lattice parameter increases over this range, revealing a decrease in film tetragonality. Although all film surfaces exhibit hydroxylation, the extent of hydroxylation is greater for the La-rich films. Rutherford backscattering spectrometry reveals that La from the film diffuses deeply into the substrate and secondary-ion-mass spectroscopy shows unambiguous Sr outdiffusion into the films.
2 More- Received 5 August 2010
DOI:https://doi.org/10.1103/PhysRevB.83.085408
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