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Title: Atomic and electronic structure of the ferroelectric BaTiO{sub 3}/Ge(001) interface

In this study, we demonstrate the epitaxial growth of BaTiO{sub 3} on Ge(001) by molecular beam epitaxy using a thin Zintl template buffer layer. A combination of density functional theory, atomic-resolution electron microscopy and in situ photoemission spectroscopy is used to investigate the electronic properties and atomic structure of the BaTiO{sub 3}/Ge interface. Aberration-corrected scanning transmission electron micrographs reveal that the Ge(001) 2 × 1 surface reconstruction remains intact during the subsequent BaTiO{sub 3} growth, thereby enabling a choice to be made between several theoretically predicted interface structures. The measured valence band offset of 2.7 eV matches well with the theoretical value of 2.5 eV based on the model structure for an in-plane-polarized interface. The agreement between the calculated and measured band offsets, which are highly sensitive to the detailed atomic arrangement, indicates that the most likely BaTiO{sub 3}/Ge(001) interface structure has been identified.
Authors:
; ; ;  [1] ; ;  [2] ;  [3]
  1. Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)
  2. Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)
  3. LeRoy Eyring Center for Solid State Science, Arizona State University, Tempe, Arizona 85287 (United States)
Publication Date:
OSTI Identifier:
22300263
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BARIUM COMPOUNDS; BUFFERS; CRYSTAL GROWTH; DENSITY FUNCTIONAL METHOD; ELECTRON MICROSCOPY; ELECTRONIC STRUCTURE; ELECTRONS; FERROELECTRIC MATERIALS; GERMANIUM; INTERFACES; LAYERS; MOLECULAR BEAM EPITAXY; PHOTOEMISSION; RESOLUTION; SPECTROSCOPY; SURFACES; TITANATES; TRANSMISSION