Novel solid solutions of Ca3-1.5xYbx square 0.5xB2SiO8: Synthesis, crystal structure, luminescence and thermal properties

作者：Yukhno Valentina; Bubnova Rimma^*; Povolotskiy Alexey; Volkov Sergey; Kolesnikov Ilya; Krzhizhanovskaya Maria; Ugolkov Valery

来源：Solid State Sciences, 2018, 83: 82-89.

DOI：10.1016/j.solidstatesciences.2018.07.002

• Borosilicates
• Crystal structure
• Polymorphic transition
• Solid solution
• Luminescence
• Thermal expansion

New cation-deficient solid solutions of Ca3-1.5xYbx square 0.5xB2SiO8 (x = 0-0.4) based on Ca3B2SiO8 borosilicate were synthesized. It was found that solid solutions in the range 0 <= x < 0.125 are structurally similar to the low-temperature monoclinic beta-Ca3B2SiO8, whereas those of the range 0.187 < x < 0.4 are similar to the high-temperature orthorhombic alpha-Ca3B2SiO8. The crystal structures of solid solutions with x = 0.2 and 0.3 were determined from single crystal X-ray diffraction data and refined in the orthorhombic space group Pnma to R-obs = 0.051 and 0.057, respectively. Thermal expansion of the samples with x = 0.1, 0.3 was investigated using powder high-temperature X-ray diffraction in the temperature range of 20-800 degrees C. Photoluminescence spectra of Ca3-1.5xYbx square 0.5xB2SiO8 consist of the intra-configurational F-2(5/2)-F-2(7/2) transitions inside of Yb3+ ions with a maximum at 975 nm.

• 出版日期2018-9