Тип публикации: статья из журнала
Год издания: 2020
Идентификатор DOI: 10.1134/S0020168520100039
Ключевые слова: apatites, high-temperature heat capacity, lead praseodymium germanatovanadates, thermal expansion, unit-cell parameters, x-ray diffraction
Аннотация: Abstract: Pb10 –xPrx(GeO4)2 +x(VO4)4– x (x = 0, 1, 2, 3) apatites have been prepared by solid-state reactions via sequential firing of appropriate oxide mixtures (PbO, Pr2O3, GeO2, and V2O5) in air in the temperature range 773–1073 K. Their unit-cell parameters have been determined as functions of temperature by high-temperature X-Показать полностьюray diffraction measurements, and the linear and volume expansion coefficients of Pb7Pr3(GeO4)5(VO4) have been calculated. The heat capacity of the synthesized Pb10 –xPrx(GeO4)2 +x(VO4)4– x (x = 0, 1, 2, 3) compounds with the apatite structure has been determined by differential scanning calorimetry in the temperature range 350–1050 K. The cp(T) curves of the samples with x = 1, 2, and 3 have been shown to have extrema (in particular, peaks at 701, 917, and 1018 K for the x = 3 sample) due to phase transitions. The experimental Cp(T) heat capacity data have been used to evaluate the thermodynamic functions of the synthesized apatites. © 2020, Pleiades Publishing, Ltd.
Журнал: Inorganic Materials
Выпуск журнала: Vol. 56, Is. 10
Номера страниц: 1027-1032
ISSN журнала: 00201685
Издатель: Pleiades journals