The new compounds Li 2 Mg 2 Si 2 S 6 and Li 2 Mg 2 Ge 2 S 6 have been prepared via traditional high-temperature, solid-state synthesis. The title compounds crystallize in the polar, noncentrosymmetric, trigonal space group P31m (No. 157) and adopt a new structure type featuring staggered, ethane-like (T 2 S 6 ) 6À units, where T = Si or Ge. These (T 2 S 6 ) 6À units are nestled within the holes of magnesium-sulfide "layers" that are created through the edge-sharing of MgS 6 octahedra. The holes found in the lithium-sulfide "layers", created by LiS 6 edge-sharing octahedra, remain vacant, containing no (T 2 S 6 ) 6À anionic group. Through the face sharing of the respective MgS 6 and LiS 6 octahedra, the magnesium-sulfide and lithium-sulfide "layers" are stitched together resulting in an overall three-dimensional structure. The optical bandgaps of Li 2 Mg 2 Si 2 S 6 and Li 2 Mg 2 Ge 2 S 6 are 3.24 and 3.18 eV, respectively, as estimated from optical diffuse reflectance UV-Vis-NIR spectroscopy. The compounds exhibit second harmonic generation responses of ~0.24 × KDP and ~2.92 × αquartz for Li 2 Mg 2 Si 2 S 6 and ~0.17 × KDP and ~2.08 × α-quartz for Li 2 Mg 2 Ge 2 S 6 , using a Nd:YAG laser at 1.064 μm. Electronic structure calculations were performed using density functional theory and the linearized augmented plane-wave approach within the WIEN2k software package. Examination of the electronic band structures shows that these compounds are indirect bandgap semiconductors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.