Surface energetics of wurtzite and sphalerite polymorphs of zinc sulfide and implications for their formation in nature. (1st January 2023)

• Record Type: Journal Article
• Authors: Subramani, Tamilarasan; Lilova, Kristina; Householder, Megan; Yang, Shuhao; Lyons, James; Navrotsky, Alexandra
• Is Part Of: Geochimica et cosmochimica acta. Volume 340(2023)
• Page Start: 99
• Page End: 107
• Publication Date: 2023-01-01
• Subjects: Surface energy -- Stability crossover -- Nano sphalerite – wurtzite transformation -- Exoplanets atmosphere -- Sulfide ores; Geochemistry -- Periodicals; Meteorites -- Periodicals; Géochimie -- Périodiques; Météorites -- Périodiques; Geochemie; Astrochemie; Electronic journals; 551.905
• DOI: 10.1016/j.gca.2022.11.003
• Languages: English
• ISSNs: 0016-7037

Abstract

Abstract: Surface energetics of zinc sulfide nanoparticles determines their structure, properties, and occurrence. Using a combination of experimental techniques, we investigated the thermodynamics of the two polymorphs, sphalerite and wurtzite at bulk and nanoscale to understand their occurrence. Calorimetric measurements confirmed that wurtzite has a lower surface energy than sphalerite, which causes a reversal in phase stability at the nanoscale, with wurtzite energetically stable for particle size below 10 nm. Taking these surface energies into account, a simple model of the thermodynamics of the sphalerite - wurtzite transformation as a function of particle size and temperature can explain the occurrence of the zinc sulfide polymorphs in environments as diverse as ore bodies and planetary atmospheres.