Synthesis and crystal structure of a new acentric oxyfluoride: Ba2TiOF6
作者:M.P. Crosnier、J.L. Fourquet
DOI:10.1016/0022-4596(92)90324-o
日期:1992.8
Ba2TiOF6 is a new oxyfluoride obtained in single-crystal form by hydrothermal synthesis. The structure was solved by X-Ray diffraction data from a single crystal using 2688 independent reflections (R = 0.018 − Rw = 0.020). Ba2TiOF6 crystallizes in the monoclinic system (S.G.:Cc, acentric) with a = 11.446(2)Å, b = 9.304(2)Å, c = 7.252(1)Å, β = 126.67(2)°, and Z = 4. The structure is built up from TiO2F4
A narrow-band red emitting BaTiF6:Mn4+phosphor with a microspindle morphology is applied to warm white LEDs by combination with a blue chip and YAG:Ce3+.
Biocatalytic Synthesis of a Nanostructured and Crystalline Bimetallic Perovskite-like Barium Oxofluorotitanate at Low Temperature
作者:Richard L. Brutchey、Edward S. Yoo、Daniel E. Morse
DOI:10.1021/ja063107g
日期:2006.8.1
Silicatein, an enzymatic biocatalyst from the marine sponge Tethya aurantia, is demonstrated to catalyze and template the hydrolysis/condensation of the molecular precursor BaTiF(6) at low temperature to form nanocrystalline BaTiOF(4), an orthorhombic oxofluorotitanate. The kinetics of hydrolysis and growth were studied in-situ via pH profiling and quartz crystal microbalance (QCM) techniques. The composition and structure of the resulting BaTiOF(4) microstructures on the silicatein surface were characterized using FT-IR spectroscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction. The silicatein-mediated hydrolysis/condensation of BaTiF(6) generates nanocrystalline BaTiOF(4) (a high temperature intermediate to BaTiO(3)) at 16 degrees C without any added acid or base, and the growth is templated along the protein filaments into floret microstructures. The unique combination of silicatein and the single-source molecular precursor has allowed a multimetallic perovskite-like material to be biocatalytically synthesized, in vitro, for the first time.