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γ-BaB2O4: High-Pressure High-Temperature Polymorph of Barium Borate with Edge-Sharing BO4 Tetrahedraстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Bekker Tatyana B., Podborodnikov Ivan V., Sagatov Nursultan E., Shatskiy Anton, Rashchenko Sergey, Sagatova Dinara N., Davydov Alexey, Litasov Konstantin D.
- Журнал: Inorganic Chemistry
- Том: 61
- Номер: 4
- Год издания: 2022
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 2340
- Последняя страница: 2350
- DOI: 10.1021/acs.inorgchem.1c03760
- Аннотация: ABSTRACT: The α- and β-modifications of barium metaborate areimportant functional materials used in optoelectronic devices. A newtheoretically predicted modification of BaB2O4 has been synthesizedunder conditions of 3 GPa and 900 °C, using the DIA-typeapparatus. The new high-pressure modification, γ-BaB2O4, crystallizesin a centrosymmetrical group of monoclinic syngony (P21/n(#14), a = 4.6392(4) Å, b = 10.2532(14) Å, c = 7.066(1) Å, β =91.363(10)°, Z = 4). A distinctive feature of the γ-BaB2O4 structureis the presence of edge-sharing tetrahedra [B2O6] which forminfinite double chains ∞[B4O4O8/2] stretching along the a axis. Thenumber of known structural types with the [B2O6] group is limited.Phase γ-BaB2O4 has the shortest distance between boron atoms ofshared tetrahedra among all currently known compounds. The[B2O6] group angles are 95.5° and 105.5°. Thermodynamic stability and electronic properties of the γ-BaB2O4 modification werestudied. The width of the band gap, calculated using the HSE06 functional, is 7.045 eV which implies transparency in the deep-UVregion. Experimental and numerical methods which demonstrate a good match were used to the study the Raman spectra of γ-BaB2O4 and β-BaB2O4 modifications. In the Raman spectra of γ-BaB2O4, the most intense band at a frequency of 853 cm−1 wasfound to correspond to the symmetric bending mode of the B−O−B−O ring in edge-sharing tetrahedra.
- Добавил в систему: Беккер Татьяна Борисовна