Microstructure of compositionally-graded (Ba{sub 1-x}Sr{sub x})TiO{sub 3} thin films epitaxially grown on La{sub 0.5}Sr{sub 0.5}CoO{sub 3}-covered (100) LaAlO{sub 3} substrates by pulsed laser deposition

Journal Article · Sun May 01 04:00:00 EDT 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1882766· OSTI ID:20713907

Xinhua, Zhu; Chan, H L.-W.; Choy, C -L; Wong, K -H; Hesse, Dietrich ^[1]

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1. National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University, Nanjing 210093 (China) and Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Germany)

Compositionally-graded (Ba{sub 1-x}Sr{sub x})TiO{sub 3} (BST) epitaxial thin films (with x decreasing from 0.25 to 0.0) were deposited by pulsed laser deposition on (100)LaAlO{sub 3} (LAO) single-crystal substrates covered with a conductive La{sub 0.5}Sr{sub 0.5}CoO{sub 3} (LSCO) layer as a bottom electrode. X-ray and electron diffraction patterns demonstrate that the entire graded film has a single-crystal cubic structure. The epitaxial relationship between BST, LSCO, and LAO can be described as (100){sub BST} parallel (100){sub LSCO} parallel (100){sub LAO}; [001]{sub BST} parallel [001]{sub LSCO} parallel [001]{sub LAO}. Cross-sectional transmission electron microscopy (TEM) images reveal that both the BST films and the LSCO bottom electrodes have sharp interfaces and overall uniform thickness across the entire specimen, and that they grow with a columnar structure. Planar TEM images show that the graded films exhibit granular and/or polyhedral morphologies with an average grain size of 50 nm. High-resolution TEM images reveal aligned rectangular-shaped voids in the graded BST film, with length size of 12-17 nm, and width of 5-8 nm along the <001> direction in the (100) plane.

• OSTI ID: 20713907
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 97; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
BARIUM COMPOUNDS
ELECTRON DIFFRACTION
ENERGY BEAM DEPOSITION
EPITAXY
GRAIN SIZE
IMAGES
LANTHANUM COMPOUNDS
LASER RADIATION
MICROWAVE RADIATION
MONOCRYSTALS
MORPHOLOGY
PERMITTIVITY
PULSED IRRADIATION
STRONTIUM TITANATES
SUBSTRATES
THIN FILMS
TITANIUM OXIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION