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Reconstructive phase transition in (NH4)3TiF7 accompanied by the ordering of TiF6 octahedra / M. S. Molokeev [et al.]> // Acta Crystallogr. B. - 2014. - Vol. 70. - P. 924-931, DOI 10.1107/S2052520614021192. - This study was supported by Russian Fund of Basic Research, project No. 12-02-00056 a
. - ISSN 0108-7681. - ISSN 1600-5740 Перевод заглавия: Реконструктивный фазовый переход в (NH4)3TiF7, сопровождающийся упорядочением октаэдров TiF6РУБ Crystallography Рубрики: CRYSTAL-STRUCTURE NEUTRON-DIFFRACTION POWDER DIFFRACTION FLUORIDES DISORDER MECHANISM PATHWAYS COMPLEX LI3THF7 ALPHA Кл.слова (ненормированные): reconstructive phase transition -- ammonium heptafluorotitanate -- order-disorder transition Аннотация: An unusual phase transition P4/mnc →Pa3 has been detected after cooling the (NH4)3TiF7 compound. Some TiF6 octahedra, which are disordered in the room-temperature tetragonal structure, become ordered in the low-temperature cubic phase due to the disappearance of the fourfold axis. Other TiF6 octahedra undergo large rotations resulting in huge displacements of the F atoms by 1.5-1.8 Å that implies a reconstructive phase transition. It was supposed that phases P4/mbm and Pm3m could be a high-temperature phase and a parent phase, respectively, in (NH4)3TiF7. Therefore, the sequence of phase transitions can be written as Pm3m → P4/bm → P4/mnc → Pa3. The interrelation between (NH4)3TiF7, (NH4)3GeF7 and (NH4)3PbF7 is found, which allows us to suppose phase transitions in relative compounds.
Смотреть статью, Смотреть статью (Wiley Online Library), Scopus, WoS, WOS, Читать в сети ИФ Держатели документа: LV Kirenskii Inst Phys, Krasnoyarsk 660036, Russia Siberian State Univ, Inst Engn Phys & Radioelect, Krasnoyarsk 660074, Russia Inst Chem, Vladivostok 660022, Russia Доп.точки доступа: Molokeev, M. S.; Молокеев, Максим Сергеевич; Misjul, S. V.; Мисюль, Сергей Валентинович; Flerov, I. N.; Флёров, Игорь Николаевич; Laptash, N. M. } Найти похожие
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