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Growth and Optical Properties of Li<sub><i>x</i></sub>Na<sub>1–<i>x</i></sub>Ba<sub>12</sub>(BO<sub>3</sub>)<sub>7</sub>F<sub>4</sub> Fluoride Borates with “Antizeolite” Structure

DOI

32

Citations

24

References

2017

Year

Tatyana B. Bekker, Sergey V. Rashchenko, V. P. Solntsev, Alexander Yèlisseyev, Alexander A. Kragzhda, V. V. Bakakin, Yuriy V. Seryotkin, A.B. Kuznetsov
Inorganic Chemistry

Abstract

Studied Li<sub>x</sub>Na<sub>1-x</sub>Ba<sub>12</sub>(BO<sub>3</sub>)<sub>7</sub>F<sub>4</sub> (P4<sub>2</sub>bc) solid solution belongs to the new class of "antizeolite" borates with [Ba<sub>12</sub>(BO<sub>3</sub>)<sub>6</sub>]<sup>6+</sup> cation pattern, which contains channels filled by anionic clusters. Optical-quality crystals were grown from the compositions with different sodium-lithium ratio. The results of Rietveld refinement based on powder data demonstrate linear increase of parameter a and unit cell volume with Na/(Na + Li) ratio in cation site. Parameter c is less sensitive to the changes in stoichiometry, which is consistent with channel topology of Li<sub>x</sub>Na<sub>1-x</sub>Ba<sub>12</sub>(BO<sub>3</sub>)<sub>7</sub>F<sub>4</sub> structure. Distinctive feature of Li<sub>x</sub>Na<sub>1-x</sub>Ba<sub>12</sub>(BO<sub>3</sub>)<sub>7</sub>F<sub>4</sub> crystals is their deep purple color, which is due to both hole-type and electron-type centers. Crystals are characterized by linear dichroism effect.

References

YearCitations

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