Polymorphism and Second Harmonic Generation in a Novel Diamond-like Semiconductor: Li2MnSnS4
Journal of Solid State Chemistry
Sulfide, Polymorphism, Stannite, Kesterite, SHG
High-temperature, solid-state synthesis in the Li2MnSnS4 system led to the discovery of two new polymorphic compounds that were analyzed using single crystal X-ray diffraction. The α-polymorph crystallizes in Pna21 with the lithium cobalt (II) silicate, Li2CoSiO4, structure type, where Z=4, R1=0.0349 and wR2=0.0514 for all data. The β-polymorph possesses the wurtz-kesterite structure type, crystallizing in Pn with Z=2, R1=0.0423, and wR2=0.0901 for all data. Rietveld refinement of synchrotron X-ray powder diffraction was utilized to quantify the phase fractions of the polymorphs in the reaction products. The α/β-Li2MnSnS4 mixture exhibits an absorption edge of ∼2.6–3.0 eV, a wide region of optical transparency in the mid- to far-IR, and moderate SHG activity over the fundamental range of 1.1–2.1 μm. Calculations using density functional theory indicate that the ground state energies and electronic structures for α- and β-Li2MnSnS4, as well as the hypothetical polymorph, γ-Li2MnSnS4 with the wurtz-stannite structure type, are highly similar.
Devlin, K. P., Glaid, A. J., Brant, J. A., Zhang, J., Srnec, M. N., Clark, D. J., Kim, Y. S., Jang, J. I., Daley, K. R., Moreau, M. A., Madura, J. D., & Aitken, J. A. (2015). Polymorphism and Second Harmonic Generation in a Novel Diamond-like Semiconductor: Li2MnSnS4. Journal of Solid State Chemistry, 231, 256 - 266. https://doi.org/10.1016/j.jssc.2015.08.011. Retrieved from https://nsuworks.nova.edu/cnso_chemphys_facarticles/175