Stoichiometry of LaAlO{sub 3} films grown on SrTiO{sub 3} by pulsed laser deposition

Journal Article · Sun Jul 14 04:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4811821· OSTI ID:22122809

Golalikhani, M.; Lei, Q. Y.; Xi, X. X. ^[1]; Chen, G.; Spanier, J. E.; Ghassemi, H.; Johnson, C. L.; Taheri, M. L. ^[2]

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1. Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States)
2. Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States)

We have studied the stoichiometry of epitaxial LaAlO{sub 3} thin films on SrTiO{sub 3} substrate grown by pulsed laser deposition as a function of laser energy density and oxygen pressure during the film growth. Both x-ray diffraction ({theta}-2{theta} scan and reciprocal space mapping) and transmission electron microscopy (geometric phase analysis) revealed a change of lattice constant in the film with the distance from the substrate. Combined with composition analysis using x-ray fluorescence we found that the nominal unit-cell volume expanded when the LaAlO{sub 3} film was La-rich, but remained near the bulk value when the film was La-poor or stoichiometric. La excess was found in all the films deposited in oxygen pressures lower than 10{sup -2} Torr. We conclude that the discussion of LaAlO{sub 3}/SrTiO{sub 3} interfacial properties should include the effects of cation off-stoichiometry in the LaAlO{sub 3} films when the deposition is conducted under low oxygen pressures.

• OSTI ID: 22122809
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 114; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
ENERGY BEAM DEPOSITION
ENERGY DENSITY
EPITAXY
FLUORESCENCE
INTERFACES
LANTHANUM COMPOUNDS
LASER RADIATION
LATTICE PARAMETERS
LAYERS
PHASE STUDIES
PULSED IRRADIATION
STOICHIOMETRY
STRONTIUM TITANATES
SUBSTRATES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION
X-RAY DIFFRACTION
X-RAY FLUORESCENCE ANALYSIS