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Title: Composition gradient effects on strain relaxation in Sr-doped LaMnO{sub 3} epitaxial thin films

The authors report on a novel method to fabricate Sr-doped composition gradient epitaxial La{sub 1−x}Sr{sub x}MnO{sub 3} thin films by radio frequency magnetron sputtering. Biaxially strained epitaxial La{sub 1−x}Sr{sub x}MnO{sub 3} thin films were grown on (001) LaAlO{sub 3} substrates by following a cosputtering procedure from LaMnO{sub 3} and La{sub 0.67}Sr{sub 0.33}MnO{sub 3} targets. Three depositions were conducted by varying the substrate temperature (750 and 850 °C) and controlling the relative deposition rate from the two targets by varying their power rate during sputtering. The thickness of the thin films was about 20 and 30 nm for the short and long duration deposition, respectively. The films were studied by symmetric θ–2θ x-ray diffraction, pole figure analysis, atomic force microscopy, and x-ray photoelectron spectroscopy. Fabrication of smooth, composition gradient films of high epitaxial quality was achieved at a substrate temperature of 850 °C and low sputtering rate. A novel strain relaxation mechanism is also found that decreases significantly the mismatch between the film and substrate as the Sr doping level increases. The reported deposition procedure can produce new possibilities of designing nanoscale structures with cross coupled properties that may result in new materials.
Authors:
;  [1]
  1. Department of Material Science and Engineering, University of Texas at Arlington, Arlington, Texas 76019 (United States)
Publication Date:
OSTI Identifier:
22479713
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 4; Other Information: (c) 2015 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 42 ENGINEERING; ATOMIC FORCE MICROSCOPY; DEPOSITION; DESIGN; DOPED MATERIALS; EPITAXY; FABRICATION; LANTHANUM COMPOUNDS; MAGNETRONS; MANGANATES; NANOSTRUCTURES; RADIOWAVE RADIATION; RELAXATION; SPUTTERING; STRAINS; SUBSTRATES; THIN FILMS; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY