L. T. Denisova, D. V. Belokopytova, Yu. F. Kargin, G. V. Vasil’ev, N. V. Belousova, V. M. Denisov
{"title":"320-1050 K 范围内 CaYb2Ge4O12 和 CaLu2Ge4O12 锗酸盐的合成与热力学研究","authors":"L. T. Denisova, D. V. Belokopytova, Yu. F. Kargin, G. V. Vasil’ev, N. V. Belousova, V. M. Denisov","doi":"10.1134/s0036023624601958","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Germanates CaYb<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub> and CaLu<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub> have been prepared via firing the solid precursor oxides CaO, Yb<sub>2</sub>O<sub>3</sub> (Lu<sub>2</sub>O<sub>3</sub>), and GeO<sub>2</sub> in air at 1223–1423 K. The X-ray diffraction crystal structures of the prepared germanates have been determined. The high-temperature heat capacity in the range 320–1050 K has been measured by differential scanning calorimetry (DSC). The measured heat capacities are well fitted by the Maier–Kelley equation: <i>C</i><sub><i>p</i></sub>(CaYb<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub>) = <span>\\(\\left( {{{416}}{{.4\\; \\pm \\;0}}{{.40}}} \\right) + \\left( {{{72}}{{.67\\; \\pm \\;2}}{{.30}}} \\right){{ \\times 1}}{{{{0}}}^{{{{-3}}}}}T - \\left( {{{50}}{{.13\\; \\pm \\;0}}{{.19}}} \\right){{ \\times 1}}{{{{0}}}^{{{5}}}}{{T}^{{{{-2}}}}}\\)</span>, and <i>C</i><sub><i>p</i></sub>(CaLu<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub>) = <span>\\(\\left( {{{450}}{{.0\\; \\pm \\;1}}{{.75}}} \\right) + \\left( {{{15}}{{.46\\; \\pm \\;1}}{{.90}}} \\right){{ \\times 1}}{{{{0}}}^{{{{-3}}}}}T - \\left( {{{78}}{{.67\\; \\pm \\;1}}{{.60}}} \\right){{ \\times 1}}{{{{0}}}^{{{5}}}}{{T}^{{{{-2}}}}}\\)</span>. These results have been used to calculate selected thermodynamic properties of the prepared germanates.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Synthesis and Thermodynamic Study of CaYb2Ge4O12 and CaLu2Ge4O12 Germanates in the Range 320–1050 K\",\"authors\":\"L. T. Denisova, D. V. Belokopytova, Yu. F. Kargin, G. V. Vasil’ev, N. V. Belousova, V. M. Denisov\",\"doi\":\"10.1134/s0036023624601958\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<h3 data-test=\\\"abstract-sub-heading\\\">Abstract</h3><p>Germanates CaYb<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub> and CaLu<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub> have been prepared via firing the solid precursor oxides CaO, Yb<sub>2</sub>O<sub>3</sub> (Lu<sub>2</sub>O<sub>3</sub>), and GeO<sub>2</sub> in air at 1223–1423 K. The X-ray diffraction crystal structures of the prepared germanates have been determined. The high-temperature heat capacity in the range 320–1050 K has been measured by differential scanning calorimetry (DSC). The measured heat capacities are well fitted by the Maier–Kelley equation: <i>C</i><sub><i>p</i></sub>(CaYb<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub>) = <span>\\\\(\\\\left( {{{416}}{{.4\\\\; \\\\pm \\\\;0}}{{.40}}} \\\\right) + \\\\left( {{{72}}{{.67\\\\; \\\\pm \\\\;2}}{{.30}}} \\\\right){{ \\\\times 1}}{{{{0}}}^{{{{-3}}}}}T - \\\\left( {{{50}}{{.13\\\\; \\\\pm \\\\;0}}{{.19}}} \\\\right){{ \\\\times 1}}{{{{0}}}^{{{5}}}}{{T}^{{{{-2}}}}}\\\\)</span>, and <i>C</i><sub><i>p</i></sub>(CaLu<sub>2</sub>Ge<sub>4</sub>O<sub>12</sub>) = <span>\\\\(\\\\left( {{{450}}{{.0\\\\; \\\\pm \\\\;1}}{{.75}}} \\\\right) + \\\\left( {{{15}}{{.46\\\\; \\\\pm \\\\;1}}{{.90}}} \\\\right){{ \\\\times 1}}{{{{0}}}^{{{{-3}}}}}T - \\\\left( {{{78}}{{.67\\\\; \\\\pm \\\\;1}}{{.60}}} \\\\right){{ \\\\times 1}}{{{{0}}}^{{{5}}}}{{T}^{{{{-2}}}}}\\\\)</span>. These results have been used to calculate selected thermodynamic properties of the prepared germanates.</p>\",\"PeriodicalId\":762,\"journal\":{\"name\":\"Russian Journal of Inorganic Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.8000,\"publicationDate\":\"2024-09-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Russian Journal of Inorganic Chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://doi.org/10.1134/s0036023624601958\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Journal of Inorganic Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1134/s0036023624601958","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
Synthesis and Thermodynamic Study of CaYb2Ge4O12 and CaLu2Ge4O12 Germanates in the Range 320–1050 K
Abstract
Germanates CaYb2Ge4O12 and CaLu2Ge4O12 have been prepared via firing the solid precursor oxides CaO, Yb2O3 (Lu2O3), and GeO2 in air at 1223–1423 K. The X-ray diffraction crystal structures of the prepared germanates have been determined. The high-temperature heat capacity in the range 320–1050 K has been measured by differential scanning calorimetry (DSC). The measured heat capacities are well fitted by the Maier–Kelley equation: Cp(CaYb2Ge4O12) = \(\left( {{{416}}{{.4\; \pm \;0}}{{.40}}} \right) + \left( {{{72}}{{.67\; \pm \;2}}{{.30}}} \right){{ \times 1}}{{{{0}}}^{{{{-3}}}}}T - \left( {{{50}}{{.13\; \pm \;0}}{{.19}}} \right){{ \times 1}}{{{{0}}}^{{{5}}}}{{T}^{{{{-2}}}}}\), and Cp(CaLu2Ge4O12) = \(\left( {{{450}}{{.0\; \pm \;1}}{{.75}}} \right) + \left( {{{15}}{{.46\; \pm \;1}}{{.90}}} \right){{ \times 1}}{{{{0}}}^{{{{-3}}}}}T - \left( {{{78}}{{.67\; \pm \;1}}{{.60}}} \right){{ \times 1}}{{{{0}}}^{{{5}}}}{{T}^{{{{-2}}}}}\). These results have been used to calculate selected thermodynamic properties of the prepared germanates.
期刊介绍:
Russian Journal of Inorganic Chemistry is a monthly periodical that covers the following topics of research: the synthesis and properties of inorganic compounds, coordination compounds, physicochemical analysis of inorganic systems, theoretical inorganic chemistry, physical methods of investigation, chemistry of solutions, inorganic materials, and nanomaterials.