Juraj Majzlan, Marek Tuhý, Edgar Dachs, Artur Benisek
{"title":"Phrasic(FeSb2O\\_4\\)和Triuhite(FeSbO\\_4)的热力学","authors":"Juraj Majzlan, Marek Tuhý, Edgar Dachs, Artur Benisek","doi":"10.1007/s00269-023-01249-2","DOIUrl":null,"url":null,"abstract":"<div><p>In this work, we investigated the thermodynamic properties of synthetic schafarzikite (FeSb<sub>2</sub>O<span>\\(_4\\)</span>) and tripuhyite (FeSbO<span>\\(_4\\)</span>). Low-temperature heat capacity (<span>\\(C_p\\)</span>) was determined by relaxation calorimetry. From these data, third-law entropy was calculated as <span>\\(110.7\\pm 1.3\\)</span> J mol<span>\\(^{-1}\\)</span>K<span>\\(^{-1}\\)</span> for tripuhyite and <span>\\(187.1\\pm 2.2\\)</span> J mol<span>\\(^{-1}\\)</span> K<span>\\(^{-1}\\)</span> for schafarzikite. Using previously published <span>\\(\\Delta _fG^o\\)</span> values for both phases, we calculated their <span>\\(\\Delta _fH^o\\)</span> as <span>\\(-947.8\\pm 2.2\\)</span> for tripuhyite and <span>\\(-1061.2\\pm 4.4\\)</span> for schafarzikite. The accuracy of the data sets was tested by entropy estimates and calculation of <span>\\(\\Delta _fH^o\\)</span> from estimated lattice energies (via Kapustinskii equation). Measurements of <span>\\(C_p\\)</span> above <span>\\(T = 300\\)</span> K were augmented by extrapolation to <span>\\(T = 700\\)</span> K with the frequencies of acoustic and optic modes, using the Kieffer <span>\\(C_p\\)</span> model. A set of equilibrium constants (<span>\\(\\log K\\)</span>) for tripuhyite, schafarzikite, and several related phases was calculated and presented in a format that can be employed in commonly used geochemical codes. Calculations suggest that tripuhyite has a stability field that extends over a wide range of pH-p<span>\\(\\epsilon\\)</span> conditions at <span>\\(T = 298.15\\)</span> K. Schafarzikite and hydrothermal oxides of antimony (valentinite, kermesite, and senarmontite) can form by oxidative dissolution and remobilization of pre-existing stibnite ores.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2023-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-023-01249-2.pdf","citationCount":"0","resultStr":"{\"title\":\"Thermodynamics of schafarzikite (FeSb2O\\\\(_4\\\\)) and tripuhyite (FeSbO\\\\(_4\\\\))\",\"authors\":\"Juraj Majzlan, Marek Tuhý, Edgar Dachs, Artur Benisek\",\"doi\":\"10.1007/s00269-023-01249-2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In this work, we investigated the thermodynamic properties of synthetic schafarzikite (FeSb<sub>2</sub>O<span>\\\\(_4\\\\)</span>) and tripuhyite (FeSbO<span>\\\\(_4\\\\)</span>). Low-temperature heat capacity (<span>\\\\(C_p\\\\)</span>) was determined by relaxation calorimetry. From these data, third-law entropy was calculated as <span>\\\\(110.7\\\\pm 1.3\\\\)</span> J mol<span>\\\\(^{-1}\\\\)</span>K<span>\\\\(^{-1}\\\\)</span> for tripuhyite and <span>\\\\(187.1\\\\pm 2.2\\\\)</span> J mol<span>\\\\(^{-1}\\\\)</span> K<span>\\\\(^{-1}\\\\)</span> for schafarzikite. Using previously published <span>\\\\(\\\\Delta _fG^o\\\\)</span> values for both phases, we calculated their <span>\\\\(\\\\Delta _fH^o\\\\)</span> as <span>\\\\(-947.8\\\\pm 2.2\\\\)</span> for tripuhyite and <span>\\\\(-1061.2\\\\pm 4.4\\\\)</span> for schafarzikite. The accuracy of the data sets was tested by entropy estimates and calculation of <span>\\\\(\\\\Delta _fH^o\\\\)</span> from estimated lattice energies (via Kapustinskii equation). Measurements of <span>\\\\(C_p\\\\)</span> above <span>\\\\(T = 300\\\\)</span> K were augmented by extrapolation to <span>\\\\(T = 700\\\\)</span> K with the frequencies of acoustic and optic modes, using the Kieffer <span>\\\\(C_p\\\\)</span> model. A set of equilibrium constants (<span>\\\\(\\\\log K\\\\)</span>) for tripuhyite, schafarzikite, and several related phases was calculated and presented in a format that can be employed in commonly used geochemical codes. Calculations suggest that tripuhyite has a stability field that extends over a wide range of pH-p<span>\\\\(\\\\epsilon\\\\)</span> conditions at <span>\\\\(T = 298.15\\\\)</span> K. Schafarzikite and hydrothermal oxides of antimony (valentinite, kermesite, and senarmontite) can form by oxidative dissolution and remobilization of pre-existing stibnite ores.</p></div>\",\"PeriodicalId\":20132,\"journal\":{\"name\":\"Physics and Chemistry of Minerals\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2023-08-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://link.springer.com/content/pdf/10.1007/s00269-023-01249-2.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physics and Chemistry of Minerals\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s00269-023-01249-2\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics and Chemistry of Minerals","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1007/s00269-023-01249-2","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Thermodynamics of schafarzikite (FeSb2O\(_4\)) and tripuhyite (FeSbO\(_4\))
In this work, we investigated the thermodynamic properties of synthetic schafarzikite (FeSb2O\(_4\)) and tripuhyite (FeSbO\(_4\)). Low-temperature heat capacity (\(C_p\)) was determined by relaxation calorimetry. From these data, third-law entropy was calculated as \(110.7\pm 1.3\) J mol\(^{-1}\)K\(^{-1}\) for tripuhyite and \(187.1\pm 2.2\) J mol\(^{-1}\) K\(^{-1}\) for schafarzikite. Using previously published \(\Delta _fG^o\) values for both phases, we calculated their \(\Delta _fH^o\) as \(-947.8\pm 2.2\) for tripuhyite and \(-1061.2\pm 4.4\) for schafarzikite. The accuracy of the data sets was tested by entropy estimates and calculation of \(\Delta _fH^o\) from estimated lattice energies (via Kapustinskii equation). Measurements of \(C_p\) above \(T = 300\) K were augmented by extrapolation to \(T = 700\) K with the frequencies of acoustic and optic modes, using the Kieffer \(C_p\) model. A set of equilibrium constants (\(\log K\)) for tripuhyite, schafarzikite, and several related phases was calculated and presented in a format that can be employed in commonly used geochemical codes. Calculations suggest that tripuhyite has a stability field that extends over a wide range of pH-p\(\epsilon\) conditions at \(T = 298.15\) K. Schafarzikite and hydrothermal oxides of antimony (valentinite, kermesite, and senarmontite) can form by oxidative dissolution and remobilization of pre-existing stibnite ores.
期刊介绍:
Physics and Chemistry of Minerals is an international journal devoted to publishing articles and short communications of physical or chemical studies on minerals or solids related to minerals. The aim of the journal is to support competent interdisciplinary work in mineralogy and physics or chemistry. Particular emphasis is placed on applications of modern techniques or new theories and models to interpret atomic structures and physical or chemical properties of minerals. Some subjects of interest are:
-Relationships between atomic structure and crystalline state (structures of various states, crystal energies, crystal growth, thermodynamic studies, phase transformations, solid solution, exsolution phenomena, etc.)
-General solid state spectroscopy (ultraviolet, visible, infrared, Raman, ESCA, luminescence, X-ray, electron paramagnetic resonance, nuclear magnetic resonance, gamma ray resonance, etc.)
-Experimental and theoretical analysis of chemical bonding in minerals (application of crystal field, molecular orbital, band theories, etc.)
-Physical properties (magnetic, mechanical, electric, optical, thermodynamic, etc.)
-Relations between thermal expansion, compressibility, elastic constants, and fundamental properties of atomic structure, particularly as applied to geophysical problems
-Electron microscopy in support of physical and chemical studies
-Computational methods in the study of the structure and properties of minerals
-Mineral surfaces (experimental methods, structure and properties)