1. Ba2TeO: A new layered oxytelluride
- Author
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Theo Siegrist, Jifeng Sun, Stephen McGill, Tiglet Besara, Jeffrey B. Whalen, David J. Singh, Daniel Ramirez, and T. Tokumoto
- Subjects
Barium oxide ,Materials science ,Band gap ,Analytical chemistry ,Mineralogy ,Condensed Matter Physics ,Heat capacity ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Tetragonal crystal system ,chemistry.chemical_compound ,chemistry ,X-ray crystallography ,Density of states ,Materials Chemistry ,Ceramics and Composites ,Physical and Theoretical Chemistry ,Electronic band structure ,Single crystal - Abstract
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) A, c=9.9437(4) A, 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
- Published
- 2015
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