Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 92: Poster Session: II-VI Semiconductors & ZnO and related Materials

HL 92.4: Poster

Thursday, March 29, 2012, 16:00–19:00, Poster D

Ground state properties, excitation spectra and formation energies for the mercury chalcolgenide HgS, mercury chloride Hg2Cl2 and sulfochloride mineral Hg3S2Cl2 — •Fabiana Da Pieve¹, Dirk Lamoen¹, Johan Verbeeck¹, Koen Janssens², and Gustav Van Tendeloo¹ — ¹EMAT, Physics, Department, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium — ²XMBA, Chemistry Department, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium

We perform a study of stuctural, electronic properties and EELS response in the core loss region for several Hg compounds, with the aim of understanding the evolution of the red cinnabar (alpha-HgS) observed in several historical paintings. Calculations are performed within DFT-GGA and give results for the structural and electronic properties of alpha-HgS,beta-HgS,Hg2Cl2, and Hg3S2Cl2 polymorphs which are in good agreement with previous experimental and computational results. The electron energy loss spectra at the Cl and S K edge of the different compounds and an analysis based on energies of formation gives new insights into the darkening process.