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Title: Ba{sub 2}TeO: A new layered oxytelluride

Single crystals of the new semiconducting oxytelluride phase, Ba{sub 2}TeO, were synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba{sub 2}TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. The optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba{sub 2}TeO is highly insulating. - Graphical abstract: Starting from a simple stacking of rocksalt layers, the final structure of Ba{sub 2}TeO can be obtained by accommodation of structural strain via atom displacements. Density of states calculations and optical absorbance measurements show that Ba{sub 2}TeO has a band gap of 2.93 eV, indicative of semiconductor behavior. - Highlights: • Single crystal synthesis of a new layered oxytelluride, Ba{sub 2}TeO. • The structure features inverse PbO-type BaO layers and NaCl-type BaTe layers. • Optical absorbance show Ba{sub 2}TeO to be a semiconductor with a 2.93 eV gap. • Density of states indicate a small hybridization between Te 5p and Ba 5d states. • The BaTe (BaO) layers dominate the heat capacity at lowmore » (high) temperatures.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [2] ;  [2] ;  [1] ;  [2] ; ;  [1] ;  [3] ;  [1] ;  [2]
  1. National High Magnetic Field Laboratory, Condensed Matter Sciences Department, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310 (United States)
  2. (United States)
  3. Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States)
Publication Date:
OSTI Identifier:
22443540
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 222; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BARIUM; BARIUM OXIDES; DENSITY OF STATES; HYBRIDIZATION; MONOCRYSTALS; POWDERS; SEMICONDUCTOR MATERIALS; SPACE GROUPS; SPECIFIC HEAT; SYNTHESIS; TETRAGONAL LATTICES; X-RAY DIFFRACTION