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Title: Observation of strontium segregation in LaAlO{sub 3}/SrTiO{sub 3} and NdGaO{sub 3}/SrTiO{sub 3} oxide heterostructures by X-ray photoemission spectroscopy

LaAlO{sub 3} and NdGaO{sub 3} thin films of different thicknesses have been grown by pulsed laser deposition on TiO{sub 2}-terminated SrTiO{sub 3} single crystals and investigated by soft X-ray photoemission spectroscopy. The surface sensitivity of the measurements has been tuned by varying photon energy hν and emission angle Θ. In contrast to the core levels of the other elements, the Sr 3d line shows an unexpected splitting for higher surface sensitivity, signaling the presence of a second strontium component. From our quantitative analysis we conclude that during the growth process Sr atoms diffuse away from the substrate and segregate at the surface of the heterostructure, possibly forming strontium oxide.
Authors:
; ; ; ;  [1] ; ; ;  [2] ;  [3]
  1. Institute for Solid State Research, IFW-Dresden, P.O. Box 270116, DE-01171 Dresden (Germany)
  2. CNR-SPIN and Dipartimento di Fisica, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples (Italy)
  3. Helmholtz-Zentrum Berlin, BESSY, Albert-Einstein-Str. 15, 12489 Berlin (Germany)
Publication Date:
OSTI Identifier:
22269566
Resource Type:
Journal Article
Resource Relation:
Journal Name: APL Materials; Journal Volume: 2; Journal Issue: 1; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALUMINATES; ENERGY BEAM DEPOSITION; LANTHANUM COMPOUNDS; LASER RADIATION; MONOCRYSTALS; PHOTOEMISSION; PULSED IRRADIATION; SEGREGATION; SENSITIVITY; SOFT X RADIATION; SPECTROSCOPY; STRONTIUM; STRONTIUM OXIDES; STRONTIUM TITANATES; SUBSTRATES; THICKNESS; THIN FILMS; TITANIUM OXIDES