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Gerasimova YV, Aleksandrovsky AS, Laptash NM, Gerasimov MA, Krylov AS, Vtyurin AN, Dubrovskiy AA. Spectroscopy of structurally disordered hydrated iron fluoridotitanate in the regions of vibrational and electronic excitations. Spectrochim Acta A Mol Biomol Spectrosc 2022; 264:120244. [PMID: 34365133 DOI: 10.1016/j.saa.2021.120244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/14/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
Raman and optical absorption spectra of disordered hydrated iron fluoridotitanate (HITF) single crystal were studied. Temperature transformations of the Raman spectra indicate independent ordering processes of the [TiF6]2- and [Fe(H2O)6]2+ complexes below the structural phase transition. The absorption spectrum in the near-infrared and visible ranges includes transitions from the high spin ground state 5T2 of Fe2+ ion to the excited 5E state and a set of excited triplets. Analysis by Tanabe-Sugano method gives crystal field Dq = 490 cm-1 and Racah parameters B = 340 cm-1 and C = 1904 cm-1. Considerable decrease of B parameter as compared to the free ion value indicates a decrease of interelectron repulsion in the disordered neighborhood of Fe2+ ions.
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Affiliation(s)
- Yu V Gerasimova
- Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk, Russia; Institute of Engineering Physics and Radio Electronics, Siberian Federal University, 660079 Krasnoyarsk, Russia.
| | - A S Aleksandrovsky
- Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk, Russia; Institute of Engineering Physics and Radio Electronics, Siberian Federal University, 660079 Krasnoyarsk, Russia
| | - N M Laptash
- Institute of Chemistry, Far Eastern Branch of RAS, 690022 Vladivostok, Russia
| | - M A Gerasimov
- Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk, Russia
| | - A S Krylov
- Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk, Russia
| | - A N Vtyurin
- Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk, Russia; Institute of Engineering Physics and Radio Electronics, Siberian Federal University, 660079 Krasnoyarsk, Russia
| | - A A Dubrovskiy
- Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk, Russia
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Gerasimova YV, Oreshonkov AS, Laptash NM, Vtyurin AN, Krylov AS, Shestakov NP, Ershov AA, Kocharova AG. Nature of phase transitions in ammonium oxofluorovanadates, a vibrational spectroscopy study of (NH 4) 3VO 2F 4 and (NH 4) 3VOF 5. Spectrochim Acta A Mol Biomol Spectrosc 2017; 176:106-113. [PMID: 28088082 DOI: 10.1016/j.saa.2017.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 12/14/2016] [Accepted: 01/02/2017] [Indexed: 06/06/2023]
Abstract
Two ammonium oxofluorovanadates, (NH4)3VO2F4 and (NH4)3VOF5, have been investigated by temperature-dependent infrared and Raman spectroscopy methods to determine the nature of phase transitions (PT) in these compounds. Dynamics of quasioctahedral groups was simulated within the framework of semi-empirical approach, which justified the cis-conformation of VO2F43- (C2v) and the C4v geometry of VOF53-. The observed infrared and Raman spectra of both compounds at room temperature (RT) revealed the presence at least of two crystallographically independent octahedral groups. The first order PT at elevated temperatures is connected with a complete dynamic disordering of these groups with only single octahedral state. At lower temperatures, the octahedra are ordered and several octahedral states appear. This PT is the most pronounced in the case of (NH4)3VOF5, when at least seven independent VOF53- octahedra are present in the structure below 50K, in accordance with the Raman spectra. Ammonium groups do not take part in PTs at higher and room temperatures but their reorientational motion freezes at lower temperatures.
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Affiliation(s)
- Yu V Gerasimova
- Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia; Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk 660079, Russia
| | - A S Oreshonkov
- Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia; Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk 660079, Russia
| | - N M Laptash
- Laboratory of Optical Materials, Institute of Chemistry, FEB RAS, Vladivostok 690022, Russia
| | - A N Vtyurin
- Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia; Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk 660079, Russia
| | - A S Krylov
- Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia
| | - N P Shestakov
- Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia
| | - A A Ershov
- Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia; Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk 660079, Russia.
| | - A G Kocharova
- Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia
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Krylov AS, Molokeev MS, Misyul SV, Krylova SN, Oreshonkov AS, Ivanenko AA, Zykova VA, Ivanov YN, Sukhovsky AA, Voronov VN, Safonov IN, Vtyurin AN. Crystal structure and phase transitions of a layered perovskite-like CsScF4crystal. CrystEngComm 2016. [DOI: 10.1039/c6ce01144f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Krylov AS, Krylova SN, Vtyurin AN, Surovtsev NV, Adishev SV, Voronov VN, Oreshonkov AS. Raman spectra and phase transitions in Rb2KInF6 elpasolite. CRYSTALLOGR REP+ 2011. [DOI: 10.1134/s1063774511010159] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Vtyurin AN, Isaenko LI, Krylova SN, Yelisseyev A, Shebanin AP, Turchin PP, Zamkova NG, Zinenko VI. Raman spectra and elastic properties of KPb2Cl5 crystals. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/pssc.200405401] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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