Crystal structure of new polymorphic modification β-Ca3B2SiO8, β-α phase transition and thermal expansion of α- and β-modifications

R. S. Bubnova, S. N. Volkov, V. A. Yukhno, M. G. Krzhizhanovskaya

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Single crystals of the β-Ca3B2SiO8 new monoclinic modification have been obtained by cooling the melt of a stoichiometric composition. The crystal structure has been determined from the single crystal X-ray diffraction data and refined with R = 0.059 (wR = 0.069) in the monoclinic space group P21/m. The thermal behavior of the synthetic borosilicate has been studied. At 472 ± 5°С, a reversible phase transition of the first order occurs, leading to the formation of the orthorhombic α-Ca3B2SiO8 modification. The thermal expansion of α- and β-modifications of Ca3B2SiO8 is anisotropic: (α11 = 15, α22 = 16, α33 =–1, αV = 30 × 10–6°С–1) and α11 = 9, α22 = 28, α33 = 1, αV = 38 × 10–6°C–1, respectively.

Original languageRussian
Pages (from-to)349-358
Number of pages10
JournalGlass Physics and Chemistry
Volume42
Issue number4
DOIs
StatePublished - 10 Aug 2016

Scopus subject areas

  • Ceramics and Composites
  • Condensed Matter Physics
  • Materials Chemistry

Keywords

  • calcium borosilicate
  • crystal structure
  • thermal expansion

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