vuzbiochemiИзвестия вузов. Прикладная химия и биотехнологияProceedings of Universities. Applied Chemistry and Biotechnology2227-29252500-1558ИРНИТУ10.21285/achb.939GWYOKHvuzbiochemi-1332Research ArticleХИМИЧЕСКИЕ НАУКИCHEMICAL SCIENCESТермическое расширение и ионная проводимость K5Pb0,5Zr1,5 (MoO4)6Thermal expansion and ionic conductivity of K5Pb0,5Zr1,5 (MoO4)6https://orcid.org/0000-0003-1301-1983КовтунецЕ. В.KovtunetsE. V.

Ковтунец Евгений Викторович, научный сотрудник

670047, г. Улан-Удэ, ул. Сахьяновой, 6

Evgeniy V. Kovtunets, Researcher

6, Sakhyanova St., Ulan-Ude, 670047

kovtunets@binm.ruhttps://orcid.org/0000-0001-7498-5103СпиридоноваТ. С.SpiridonovaT. S.

Спиридонова Татьяна Сергеевна, к.х.н., старший научный сотрудник

670047, г. Улан-Удэ, ул. Сахьяновой, 6

Tatyana S. Spiridonova, Cand. Sci. (Chemistry), Senior Researcher

6, Sakhyanova St., Ulan-Ude, 670047

spiridonova@binm.ruhttps://orcid.org/0000-0003-1032-8854ТушиноваЮ. Л.TushinovaYu. L.

Тушинова Юнна Лудановна, к.х.н., доцент, научный сотрудник

670047, г. Улан-Удэ, ул. Сахьяновой, 6

Yunna L. Tushinova, Cand. Sci. (Chemistry), Associate Professor, Researcher

6, Sakhyanova St., Ulan-Ude, 670047

tushinova@binm.ruhttps://orcid.org/0000-0001-9850-2719ЛогвиноваА. В.LogvinovaA. V.

Логвинова Александра Владимировна, инженер

670047, г. Улан-Удэ, ул. Сахьяновой, 6

Alexandra V. Logvinova, Engineer

6, Sakhyanova St., Ulan-Ude, 670047

logvinova_alexsandra@bk.ruhttps://orcid.org/0000-0001-9697-6320БазароваЦ. Т.BazarovaT. T.

Базарова Цырендыжит Тушиновна, к.х.н., ведущий инженер

670047, г. Улан-Удэ, ул. Сахьяновой, 6

Tsyrendyzhit T. Bazarova, Cand. Sci. (Chemistry), Leading Enginee

6, Sakhyanova St., Ulan-Ude, 670047

basst@list.ruhttps://orcid.org/0000-0003-1712-6964БазаровБ. Г.BazarovB. G.

Базаров Баир Гармаевич, д.ф.-м.н., доцент, ведущий научный сотрудник

670047, г. Улан-Удэ, ул. Сахьяновой, 6

Bair G. Bazarov, Dr. Sci. (Physics and Mathematics), Associate Professor, Leading Researcher

6, Sakhyanova St., Ulan-Ude, 670047

jbaz@binm.ruБайкальский институт природопользования СО РАНРоссияBaikal Institute of Nature Management SB RASRussian Federation202412012025144444452Copyright © Ковтунец Е.В., Спиридонова Т.С., Тушинова Ю.Л., Логвинова А.В., Базарова Ц.Т., Базаров Б.Г., 20242024Ковтунец Е.В., Спиридонова Т.С., Тушинова Ю.Л., Логвинова А.В., Базарова Ц.Т., Базаров Б.Г.Kovtunets E.V., Spiridonova T.S., Tushinova Y.L., Logvinova A.V., Bazarova T.T., Bazarov B.G.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://vuzbiochemi.elpub.ru/jour/article/view/1332

Целью представленного исследования являлось получение нового тройного молибдата K5Pb0,5Zr1,5(MoO4)6, изоструктурного K5Pb0,5Hf1,5(MoO4)6, методом направленного синтеза по твердофазной реакции в интервале температур от 350 до 550 °С в течение 100 ч. Соединение кристаллизуется в тригональной сингонии с пространственной группой R3̅  с параметрами элементарной ячейки a = 10,6604(2) Å, c = 37,9769(9) Å, V = 3737,6(2) Å3. Структура уточнена методом Ритвельда. Положения атомов уточнены в изотропном приближении c «мягкими» ограничениями на расстояния Mo–O и углы связей O–Mo–O. Кристаллическая структура представляет собой трехмерный каркас, образующийся из октаэдров PbO6 и ZrO6 и тетраэдров MoO4, соединяющихся между собой посредством общих кислородных вершин. Термическое расширение K5Pb0,5Zr1,5(MoO4)6 исследовано методом высокотемпературной порошковой рентгенографии. Вычисленные значения коэффициентов термического расширения вдоль обоих кристаллографических осей остаются положительными во всем температурном диапазоне, при этом значение αa остается постоянным, в то время как значение αс с ростом температуры возрастает. Полученный тройной молибдат относится к материалам с высоким тепловым расширением (αV = 60×10-6 °C-1). Значительная анизотропия в кристаллографическом направлении с обусловлена «мягкими» легко деформирующимися связями K–O и Pb-O. Электропроводность K5Pb0,5Zr1,5(MoO4)6 исследована методом импедансной спектроскопии в интервале температур 30–500 °C; при 500 °C значение проводимости достигает 0,7×10-4 См/см с Еа = 0,59 эВ.

The present study is aimed at the directed synthesis of a new ternary molybdate K5Pb0.5Zr1.5(MoO4)6 isostructural to K5Pb0.5Hf1.5(MoO4)6 by solid-phase reaction within the temperature range of 350–550 °С (for 100 h). The compound crystallizes in the rhombohedral system with the space group R3̅  and unit cell parameters of a = 10.6604(2) Å, c = 37.9769(9) Å, and V = 3737.6(2) Å3. The structure was refined using the Rietveld method. The atomic positions were refined in the isotropic approximation, with soft constraints on Mo–O distances and O–Mo–O bond angles. The crystal structure constitutes a 3D scaffold comprising PbO6 and ZrO6 octahedrons and MoO4 tetrahedrons sharing oxygen vertices. The thermal expansion of K5Pb0.5Zr1.5(MoO4)6 was studied via high-temperature X-ray powder diffraction. The calculated thermal expansion coefficients along both crystallographic axes remain positive over the entire temperature range. In this case, the value of αa remains constant, while that of αc increases with rising temperature. The obtained ternary molybdate belongs to materials with high thermal expansion (αV = 60×10-6 °С-1). The significant anisotropy in the crystallographic direction c can be attributed to the soft K–O and Pb-O bonds. The electrical conductivity of K5Pb0.5Zr1.5(MoO4)6 was studied via impedance spectroscopy within the temperature range of 30–500 °С; at 500 °С, the conductivity amounted to 0.7×10-4 S/cm, with Ea = 0.59 eV.

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The authors declare that there are no conflicts of interest present.