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Title: Cation non-stoichiometry in pulsed laser deposited Sr{sub 2+y}Fe{sub 1+x}Mo{sub 1-x}O₆ epitaxial films

Sr₂FeMoO₆ (SFMO) films were grown on SrTiO₃ (100)- and (111)-oriented substrates via pulsed laser deposition (PLD). In order to study the fundamental characteristics of deposition, films were grown in two different PLD chambers. In chamber I, the best films were grown with a relatively long substrate-to-target distance (89 mm), high substrate temperature (850 °C), and low pressure (50 mTorr) in a 95% Ar/5% H₂ atmosphere. Although X-ray diffraction (XRD) measurements indicate these films are single phase, Rutherford Backscattering (RBS) measurements reveal considerable non-stoichiometry, corresponding to a Sr₂Fe{sub 1–x}Mo{sub 1+x}O₆ composition with x≅0.2–0.3. This level of non-stoichiometry results in inferior magnetic properties. In chamber II, the best films were grown with a much shorter substrate-to-target distance (38 mm), lower temperature (680 °C), and higher pressure (225 mTorr). XRD measurements show that the films are single phase, and RBS measurements indicate that they are nearly stoichiometric. The degree of ordering between Fe and Mo was dependent on both the temperature and pressure used during deposition, reaching a maximum order parameter of 85%. The saturation magnetization increases as the Fe/Mo ordering increases, reaching a maximum of 2.4 μB/f.u. Based on prior studies of bulk samples, one would expect a higher saturation magnetization formore » this degree of Fe/Mo order. The presence of extra strontium oxide layers in the form of Ruddlesden-Popper intergrowths appears to be responsible for the lower than expected saturation magnetization of these films.« less
Authors:
;  [1] ; ; ; ; ; ;  [2] ;  [3]
  1. Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210-1117 (United States)
  2. Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210-1117 (United States)
  3. Department of Physics, The Ohio State University, Columbus, Ohio 43210-1117 (United States)
Publication Date:
OSTI Identifier:
22306247
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ENERGY BEAM DEPOSITION; EPITAXY; FILMS; IRON COMPOUNDS; LASER RADIATION; LAYERS; MAGNETIC PROPERTIES; MAGNETIZATION; MOLYBDATES; RUTHERFORD BACKSCATTERING SPECTROSCOPY; SATURATION; STOICHIOMETRY; STRONTIUM COMPOUNDS; STRONTIUM OXIDES; STRONTIUM TITANATES; SUBSTRATES; X-RAY DIFFRACTION