Ames Laboratory; Chemistry
Chemistry, Ames Laboratory
Journal of the American Chemical Society
A novel barium silicon phosphide was synthesized and characterized. Ba2Si3P6 crystallizes in the noncentrosymmetric space group Pna21 (No. 33) and exhibits a unique bonding connectivity in the Si–P polyanion not found in other compounds. The crystal structure is composed of SiP4 tetrahedra connected into one-dimensional double-tetrahedra chains through corner sharing, edge sharing, and covalent P–P bonds. Chains are surrounded by Ba cations to achieve an electron balance. The novel compound exhibits semiconducting properties with a calculated bandgap of 1.6 eV and experimental optical bandgap of 1.88 eV. The complex pseudo-one-dimensional structure manifests itself in the transport and optical properties of Ba2Si3P6, demonstrating ultralow thermal conductivity (0.56 W m–1 K–1 at 300 K), promising second harmonic generation signal (0.9 × AgGaS2), as well as high laser damage threshold (1.6 × AgGaS2, 48.5 MW/cm2) when compared to the benchmark material AgGaS2. Differential scanning calorimetry reveals that Ba2Si3P6 melts congruently at 1373 K, suggesting that large single crystal growth may be possible.
DOE Contract Number(s)
Iowa State University Digital Repository, Ames IA (United States)