{"title":"Vaporisation thermodynamic studies over <U3Sn7(cr) + USn2(cr)> and <USn2(cr) + USn(cr)> biphasic regions of U-Sn system using high temperature mass spectrometry","authors":"","doi":"10.1016/j.calphad.2024.102751","DOIUrl":null,"url":null,"abstract":"<div><div>High-temperature vaporisation thermodynamic studies over <U<sub>3</sub>Sn<sub>7</sub>(cr) + USn<sub>2</sub>(cr)> and <USn<sub>2</sub>(cr) + USn(cr)> two-phase regions were carried out by employing Knudsen Effusion Mass Spectrometry (KEMS) in the temperature range 1148–1465 and 1222–1471 K, respectively. Sn(g) was the only species observed in the mass spectra of the equilibrium vapour phase over both the biphasic regions. The partial pressure-temperature relations of Sn(g) were deduced as</div><div>log(p<sub>Sn</sub>/Pa) = (−15,737 ± 73)/(T/K)) + (9.52 ± 0.06) (1148–1465 K) <U<sub>3</sub>Sn<sub>7</sub>(cr) + USn<sub>2</sub>(cr)> and</div><div>log(p<sub>Sn</sub>/Pa) = (−16,151 ± 67)/(T/K)) + (9.70 ± 0.05) (1222–1471 K) <USn<sub>2</sub>(cr) + USn(cr)></div><div>Using p-T relations, the enthalpies of the following heterogeneous reaction equilibria were evaluated by the second law method: U<sub>3</sub>Sn<sub>7</sub>(cr) = 3USn<sub>2</sub>(cr) + Sn(g) and USn<sub>2</sub>(cr) = USn(cr) + Sn(g). Subsequently, the Gibbs energies of the formation of U<sub>3</sub>Sn<sub>7</sub>(cr) and USn<sub>2</sub>(cr) were derived. Knudsen effusion mass spectrometric studies over these two biphasic regions are being reported for the first time.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0364591624000932","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
High-temperature vaporisation thermodynamic studies over <U3Sn7(cr) + USn2(cr)> and <USn2(cr) + USn(cr)> two-phase regions were carried out by employing Knudsen Effusion Mass Spectrometry (KEMS) in the temperature range 1148–1465 and 1222–1471 K, respectively. Sn(g) was the only species observed in the mass spectra of the equilibrium vapour phase over both the biphasic regions. The partial pressure-temperature relations of Sn(g) were deduced as
Using p-T relations, the enthalpies of the following heterogeneous reaction equilibria were evaluated by the second law method: U3Sn7(cr) = 3USn2(cr) + Sn(g) and USn2(cr) = USn(cr) + Sn(g). Subsequently, the Gibbs energies of the formation of U3Sn7(cr) and USn2(cr) were derived. Knudsen effusion mass spectrometric studies over these two biphasic regions are being reported for the first time.
期刊介绍:
The design of industrial processes requires reliable thermodynamic data. CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) aims to promote computational thermodynamics through development of models to represent thermodynamic properties for various phases which permit prediction of properties of multicomponent systems from those of binary and ternary subsystems, critical assessment of data and their incorporation into self-consistent databases, development of software to optimize and derive thermodynamic parameters and the development and use of databanks for calculations to improve understanding of various industrial and technological processes. This work is disseminated through the CALPHAD journal and its annual conference.