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Crystallographic and optical study of LiNb_1?-?xTa_xO₃.

ABSTRACT: Powders of lithium niobate-tantalate across the full compositional range have been made and crystals grown using a lithium vanadate flux growth technique. The Li-content of a lithium tantalate crystal has been determined using the zero-birefringence temperature and Curie measurements, confirming the Li content is between that of congruent and stoichiometric crystals. X-ray diffraction measurements show the Nb/Ta displacement and octahedral tilt both decrease as the Ta content is increased. This also results in a decrease in the lattice parameters from lithium niobate to lithium tantalate. Birefringence measurements on the crystals as a function of temperature have been used to determine the point that the crystals become zero-birefringent, and by comparison with the structural studies have confirmed that it is not related to a phase transition and the structures remain polar through the zero-birefringence points.

SUBMITTER: Huband S

PROVIDER: S-EPMC5642313 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature

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Crystallographic and optical study of LiNb1 - xTaxO3.

Huband S S Keeble D S DS Zhang N N Glazer A M AM Bartasyte A A Thomas P A PA

Acta crystallographica Section B, Structural science, crystal engineering and materials 20170601 Pt 3

Powders of lithium niobate-tantalate across the full compositional range have been made and crystals grown using a lithium vanadate flux growth technique. The Li-content of a lithium tantalate crystal has been determined using the zero-birefringence temperature and Curie measurements, confirming the Li content is between that of congruent and stoichiometric crystals. X-ray diffraction measurements show the Nb/Ta displacement and octahedral tilt both decrease as the Ta content is increased. This ...[more]

PMID: 28572559

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