Fracture-induced reconstruction of a chalcopyrite (CuFeS2) surface

• Published in: Surface and interface analysis 2003-05, Vol.35 (5), p.415-428
• Main Author: Klauber, Craig
• Format: Article
• Language: English
• Subjects: chalcopyrite; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; dimerization; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Photoemission and photoelectron spectra; Physics; pyrite; reconstruction; Solid surfaces and solid-solid interfaces; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); XPS
• ISSN: 0142-2421; 1096-9918
• DOI: 10.1002/sia.1539

Two factors contributing to the high binding energy asymmetry of the S 2p XPS peak for virginal chalcopyrite (CuFeS2) surfaces have been identified. The Cu, Fe and S 2p spectra of freshly fractured surfaces of chalcopyrite have been found to display a loss feature at ∼2.6 eV that is attributed to an interband transition S 3p → Fe 3d, from occupied S levels to unoccupied Fe levels. For leached chalcopyrite systems, intensity on that side of the S 2p peak sometimes has been interpreted erroneously in terms of oxidized species such as polysulphides. A second prominent S 2p component has been determined at a binding energy of 161.9 eV and identified as the sulphide dimer S22−. With supporting evidence, a simultaneous surface reconstruction and redox reaction model has been developed for the fracturing of chalcopyrite, leading to an exposed surface phase of about two layers thick with a 50% pyritic content. The pyritic nature of the fractured chalcopyrite surface has implications for understanding the leaching chemistry of chalcopyrite. Copyright © 2003 John Wiley & Sons, Ltd.