Compression of Silver Sulfide: X-ray Diffraction Measurements and Total-Energy Calculations

• Published in: Inorganic chemistry Vol. 51; no. 9; pp. 5289 - 5298
• Main Authors: Santamarı́a-Pérez, David, Marqués, Miriam, Chuliá-Jordán, Raquel, Menendez, José M, Gomis, Oscar, Ruiz-Fuertes, Javier, Sans, Juan A, Errandonea, Daniel, Recio, José M
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07.05.2012
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic300236p

Angle-dispersive X-ray diffraction measurements have been performed in acanthite, Ag2S, up to 18 GPa in order to investigate its high-pressure structural behavior. They have been complemented by ab initio electronic structure calculations. From our experimental data, we have determined that two different high-pressure phase transitions take place at 5 and 10.5 GPa. The first pressure-induced transition is from the initial anti-PbCl2-like monoclinic structure (space group P21/n) to an orthorhombic Ag2Se-type structure (space group P212121). The compressibility of the lattice parameters and the equation of state of both phases have been determined. A second phase transition to a P21/n phase has been found, which is a slight modification of the low-pressure structure (Co2Si-related structure). The initial monoclinic phase was fully recovered after decompression. Density functional and, in particular, GGA+U calculations present an overall good agreement with the experimental results in terms of the high-pressure sequence, cell parameters, and their evolution with pressure.