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http://hdl.handle.net/2445/184767
Title: | Engineering Polar Oxynitrides: Hexagonal Perovskite BaWON2 |
Author: | Oró-Solé, Judith Fina, Ignasi Frontera Beccaria, Carlos Gàzquez, Jaume Ritter, Clemens Cunquero, Marina Loza-Alvarez, Pablo Conejeros Espíndola, Sergio Alemany i Cahner, Pere Canadell, Enric, 1950- Fontcuberta i Griñó, Josep Fuertes, Amparo |
Keywords: | Compostos inorgànics Tungstè Ciència dels materials Inorganic compounds Tungsten Materials science |
Issue Date: | 10-Jul-2020 |
Publisher: | Wiley-VCH |
Abstract: | Non-centrosymmetric polar compounds have important technological properties. Reported perovskite oxy- nitrides show centrosymmetric structures, and for some of them high permittivities have been observed and ascribed to local dipoles induced by partial order of nitride and oxide. Reported here is the first hexagonal perovskite oxynitride BaWON2, which shows a polar 6H polytype. Synchrotron X-ray and neutron powder diffraction, and annular bright-field in scan- ning transmission electron microscopy indicate that it crystal- izes in the non-centrosymmetric space group P63mc, with a total order of nitride and oxide at two distinct coordination environments in cubic and hexagonal packed BaX3 layers. A synergetic second-order Jahn-Teller effect, supported by first principle calculations, anion order, and electrostatic repulsions between W6+ cations, induce large distortions at two inequiva- lent face-sharing octahedra that lead to long-range ordered dipoles and spontaneous polarization along the c axis. The new oxynitride is a semiconductor with a band gap of 1.1 eV and a large permittivity. |
Note: | Versió postprint del document publicat a: https://doi.org/10.1002/anie.202006519 |
It is part of: | Angewandte Chemie-International Edition, 2020, vol. 59, num. 42, p. 1-6 |
URI: | http://hdl.handle.net/2445/184767 |
Related resource: | https://doi.org/10.1002/anie.202006519 |
ISSN: | 1433-7851 |
Appears in Collections: | Articles publicats en revistes (Ciència dels Materials i Química Física) Articles publicats en revistes (Institut de Química Teòrica i Computacional (IQTCUB)) |
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714096.pdf | 2.83 MB | Adobe PDF | View/Open |
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