Anisotropic-strain-relaxation-induced crosshatch morphology in epitaxial SrTiO3/NdGaO3 thin films

X. L. Tan; F. Chen; P. F. Chen; H. R. Xu; B. B. Chen; F. Jin; G. Y. Gao; W. B. Wu

doi:10.1063/1.4897960

AIP Advances (Oct 2014)

Anisotropic-strain-relaxation-induced crosshatch morphology in epitaxial SrTiO3/NdGaO3 thin films

X. L. Tan,
F. Chen,
P. F. Chen,
H. R. Xu,
B. B. Chen,
F. Jin,
G. Y. Gao,
W. B. Wu

Affiliations

X. L. Tan: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China
F. Chen: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China
P. F. Chen: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China
H. R. Xu: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China
B. B. Chen: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China
F. Jin: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China
G. Y. Gao: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China
W. B. Wu: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230026, People’s Republic of China

DOI: https://doi.org/10.1063/1.4897960
Journal volume & issue: Vol. 4, no. 10
pp. 107109 – 107109-10

Abstract

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We investigate the strain relaxation and surface morphology of epitaxial SrTiO3 (STO) films grown on (001)O and (110)O planes of orthorhombic NdGaO3 (NGO), and (001) plane of cubic (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) substrates. Although the average lattice mismatches are similar, strikingly regular crosshatched surface patterns can be found on STO/NGO(001)O[(110)O] films, contrary to the uniform surface of STO/LSAT(001). Based on the orientation and thickness dependent patterns and high-resolution x-ray diffractions, we ascribe the crosshatch morphology to the anisotropic strain relaxation with possibly the 60° misfit dislocation formation and lateral surface step flow in STO/NGO films, while an isotropic strain relaxation in STO/LSAT. Further, we show that the crosshatched STO/NGO(110)O surface could be utilized as a template to modify the magnetotransport properties of epitaxial La0.6Ca0.4MnO3 films. This study highlights the crucial role of symmetry mismatch in determining the surface morphology of the perovskite oxide films, in addition to their epitaxial strain states, and offers a different route for designing and fabricating functional perovskite-oxide devices.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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