A universal chemical potential for sulfur vapours
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Published version
Date
2015-10-16
Authors
Jackson, Adam J.
Tiana, Davide
Walsh, Aron
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry (RSC)
Published Version
Abstract
The unusual chemistry of sulfur is illustrated by the tendency for catenation. Sulfur forms a range of open and closed S-n species in the gas phase, which has led to speculation on the composition of sulfur vapours as a function of temperature and pressure for over a century. Unlike elemental gases such as O-2 and N-2, there is no widely accepted thermodynamic potential for sulfur. Here we combine a first-principles global structure search for the low energy clusters from S-2 to S-8 with a thermodynamic model for the mixed-allotrope system, including the Gibbs free energy for all gas-phase sulfur on an atomic basis. A strongly pressure-dependent transition from a mixture dominant in S-2 to S8 is identified. A universal chemical potential function, mu(S)(T,P), is proposed with wide utility in modelling sulfurisation processes including the formation and annealing of metal chalcogenide semiconductors.
Description
Keywords
Electronic-structure , Elemental sulfur , Crystal-growth , Scale factorS , Scale factors , Free-energy , Prediction , CU2ZNSNS4 , Model , S-4 , Tetrasulfur
Citation
Jackson, A. J., Tiana, D. and Walsh, A. (2016) 'A universal chemical potential for sulfur vapours', Chemical Science, 7(2), pp. 1082-1092. doi: 10.1039/c5sc03088a