Abstract
The new quaternary thiosilicate, Li2PbSiS4 (dilithium lead silicon tetrasulfide), was prepared in an evacuated fused-silica tube via high-temperature, solid-state synthesis at 800 °C, followed by slow cooling. The crystal structure was solved and refined using single-crystal X-ray diffraction data. By strict definition, the title compound crystallizes in the stannite structure type; however, this type of structure can also be described as a compressed chalcopyrite-like structure. The Li+ cation lies on a crystallographic fourfold rotoinversion axis, while the Pb2+ and Si4+ cations reside at the intersection of the fourfold rotoinversion axis with a twofold axis and a mirror plane. The Li+ and Si4+ cations in this structure are tetrahedrally coordinated, while the larger Pb2+ cation adopts a distorted eight-coordinate dodecahedral coordination. These units join together via corner- and edge-sharing to create a dense, three-dimensional structure. Powder X-ray diffraction indicates that the title compound is the major phase of the reaction product. Electronic structure calculations, performed using the full potential linearized augmented plane wave method within density functional theory (DFT), indicate that Li2PbSiS4 is a semiconductor with an indirect bandgap of 2.22 eV, which compares well with the measured optical bandgap of 2.51 eV. The noncentrosymmetric crystal structure and relatively wide bandgap designate this compound to be of interest for IR nonlinear optics.
Funder
National Science Foundation
Publisher
International Union of Crystallography (IUCr)
Subject
Materials Chemistry,Inorganic Chemistry,Physical and Theoretical Chemistry,Condensed Matter Physics
Reference61 articles.
1. Aitken, J. A., Brant, J. A., Clark, D. J., Kim, Y. S. & Jang, J. I. (2014). Impact of Bandgap on Infrared Optical Nonlinearity in Novel Quaternary Chalcogenides: Cu2CdSnS4, α/β-Cu2ZnSiS4 and Li2CdGeS4, in Nonlinear Optics: Fundamentals, Applications and Technological Advances, edited by F. Wilkins, pp. 1-61. New York: Nova Science Publishers Inc.
2. Li2PbGeS4 and Li2EuGeS4: Polar Chalcopyrites with a Severe Tetragonal Compression
3. New Quaternary Barium Copper/Silver Selenostannates: Different Coordination Spheres, Metal−Metal Interactions, and Physical Properties
4. Synthesis and Crystal Structure Determination of (NH4)Ag2AsS4, a Further Chalcopyrite-Type Compound
5. Blaha, P., Schwarz, K., Madsen, G. K. H., Vasnicka, D. K. & Luitz, J. (2011). WIEN2K. Vienna University of Technology, Austria.
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