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Title: Surface reconstructions in molecular beam epitaxy of SrTiO{sub 3}

Abstract

We show that reflection high-energy electron diffraction (RHEED) can be used as a highly sensitive tool to track surface and resulting film stoichiometry in adsorption-limited molecular beam epitaxy of (001) SrTiO{sub 3} thin films. Even under growth conditions that yield films with a lattice parameter that is identical to that of stoichiometric bulk crystals within the detection limit of high-resolution x-ray diffraction (XRD), changes in surface reconstruction occur from (1 × 1) to (2 × 1) to c(4 × 4) as the equivalent beam pressure of the Ti metalorganic source is increased. These surface reconstructions are correlated with a shift from mixed SrO/TiO{sub 2} termination to pure TiO{sub 2} termination. The crossover to TiO{sub 2} surface termination is also apparent in a phase shift in RHEED oscillations observed at the beginning of growth. Comparison with prior results for carrier mobilities of doped films shows that the best films are grown under conditions of a TiO{sub 2}-saturated surface [c(4 × 4) reconstruction] within the XRD growth window.

Authors:
;  [1]
  1. Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)
Publication Date:
OSTI Identifier:
22391943
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 105; Journal Issue: 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ADSORPTION; CARRIER MOBILITY; CRYSTALS; DOPED MATERIALS; ELECTRON DIFFRACTION; FILMS; LATTICE PARAMETERS; MOLECULAR BEAM EPITAXY; OSCILLATIONS; PHASE SHIFT; REFLECTION; STOICHIOMETRY; STRONTIUM OXIDES; STRONTIUM TITANATES; SURFACES; TITANIUM OXIDES; X-RAY DIFFRACTION

Citation Formats

Kajdos, Adam P., and Stemmer, Susanne. Surface reconstructions in molecular beam epitaxy of SrTiO{sub 3}. United States: N. p., 2014. Web. doi:10.1063/1.4901726.
Kajdos, Adam P., & Stemmer, Susanne. Surface reconstructions in molecular beam epitaxy of SrTiO{sub 3}. United States. https://doi.org/10.1063/1.4901726
Kajdos, Adam P., and Stemmer, Susanne. 2014. "Surface reconstructions in molecular beam epitaxy of SrTiO{sub 3}". United States. https://doi.org/10.1063/1.4901726.
@article{osti_22391943,
title = {Surface reconstructions in molecular beam epitaxy of SrTiO{sub 3}},
author = {Kajdos, Adam P. and Stemmer, Susanne},
abstractNote = {We show that reflection high-energy electron diffraction (RHEED) can be used as a highly sensitive tool to track surface and resulting film stoichiometry in adsorption-limited molecular beam epitaxy of (001) SrTiO{sub 3} thin films. Even under growth conditions that yield films with a lattice parameter that is identical to that of stoichiometric bulk crystals within the detection limit of high-resolution x-ray diffraction (XRD), changes in surface reconstruction occur from (1 × 1) to (2 × 1) to c(4 × 4) as the equivalent beam pressure of the Ti metalorganic source is increased. These surface reconstructions are correlated with a shift from mixed SrO/TiO{sub 2} termination to pure TiO{sub 2} termination. The crossover to TiO{sub 2} surface termination is also apparent in a phase shift in RHEED oscillations observed at the beginning of growth. Comparison with prior results for carrier mobilities of doped films shows that the best films are grown under conditions of a TiO{sub 2}-saturated surface [c(4 × 4) reconstruction] within the XRD growth window.},
doi = {10.1063/1.4901726},
url = {https://www.osti.gov/biblio/22391943}, journal = {Applied Physics Letters},
issn = {0003-6951},
number = 19,
volume = 105,
place = {United States},
year = {Mon Nov 10 00:00:00 EST 2014},
month = {Mon Nov 10 00:00:00 EST 2014}
}