Рубрики:
Heat-capacity
Ammonium
(NH4)3TiF7
Pressure
Кл.слова (ненормированные):
Fluorides -- Structural disorder -- Phase transitions -- Entropy -- Barocaloric effect
Heat-capacity
Ammonium
(NH4)3TiF7
Pressure
Кл.слова (ненормированные):
Fluorides -- Structural disorder -- Phase transitions -- Entropy -- Barocaloric effect
Аннотация: Structural phase transition P-3m1 → P-1 of the first order and nonferroelectric nature was found in (NH4)2SnF6 at about 110 K in the process of thermal, optical, dielectric and X-ray studies. Order-disorder transformation is accompanied by large changes of entropy (ΔS0 = 16.4 J/mol K) and volume (ΔV0/V ≈ 1%). The structural model associated with three orientations of NH4 tetrahedra in P-3m1 phase and their complete ordering in P-1 phase was suggested with the entropy change (ΔS0 = 18.3 J/mol K) close to the experimental value. A good agreement between baric coefficients measured in a direct way (dT0/dp = -157 K/GPa) and evaluated using entropy and volume changes at phase transition (-170 K/GPa) was found. Barocaloric effects in (NH4)2SnF6 are comparable with those of known solid state refrigerants and are characterised by a low-pressure need for realising their maximum values. © 2015 Elsevier B.V. All rights reserved.
Смотреть статью,
Scopus,
WOS,
Для получение полного текста обратитесь в библиотеку
Держатели документа:
Kirensky Institute of Physics, Siberian Branch of RAS, Akademgorodok 50, Krasnoyarsk, Russian Federation
Institute of Engineering Physics and Radioelectronics, Siberian State University, Krasnoyarsk, Russian Federation
Astafijev Krasnoyarsk State Pedagogical University, Krasnoyarsk, Russian Federation
Krasnoyarsk State Agrarian University, Krasnoyarsk, Russian Federation
Far Eastern State Transport University, Khabarovsk, Russian Federation
Institute of Chemistry, Far Eastern Branch of RAS, Vladivostok, Russian Federation
Доп.точки доступа:
Flerov, I. N.; Флёров, Игорь Николаевич; Kartashev, A. V.; Карташев, Андрей Васильевич; Gorev, M. V.; Горев, Михаил Васильевич; Bogdanov, E. V.; Богданов, Евгений Витальевич; Mel'nikova, S. V.; Мельникова, Светлана Владимировна; Molokeev, M. S.; Молокеев, Максим Сергеевич; Pogoreltsev, E. I.; Погорельцев, Евгений Ильич; Laptash, N. M.