Single crystals of magnesium tin oxyborate, Mg5SnB 2O10 (Mg5SnO4(BO3) 2), were prepared at 1350 °C in air, using B2O 3 as a flux. They were colorless and transparent with needlelike or columnar shapes. X-ray diffraction analysis of the single crystals revealed that Mg5SnB2O10 crystallizes in the triclinic space group F1̄ (No. 2) with Z = 16, a = 6.1295(8), b = 18.714(3), c = 24.719(3) Å, α = 90.021(5)°, β = 90.032(4)°, γ = 90.041(5)°, and V = 2835.4(7) Å3 (R1 = 0.0168, wR2 = 0.0459, and S = 1.297 for all data). The crystal structure of Mg 5SnB2O10 is a ludwigite-type superstructure. Mg and Sn atoms are ordered and coordinated by six O atoms, and the edges of MO6 (where M = Mg and Sn) octahedra are connected along the a-axis and form zigzag walls. B atoms are in the spaces surrounded by the walls and are coordinated by three O atoms. Polycrystals of titanium(IV)-doped solid solutions, Mg5Sn1-xTixB2O 10 (0 < x ≤ 0.50), were also prepared by solid state reaction at 1300 °C in air. The refined unit cell volumes decreased with increasing titanium content (x), indicating partial substitution of Ti for Sn atoms. A broad blue emission with a peak wavelength of ∼430 nm was observed from the solid solutions under 265-nm ultraviolet excitation. A quantum efficiency of 0.81 was measured at room temperature for Mg5Sn0.80Ti 0.20B2O10.
ASJC Scopus subject areas
- 化学 (全般)