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Lithium tantalate single crystal stoichiometry
Author(s) -
Barns R. L.,
Carruthers J. R.
Publication year - 1970
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889870006490
Subject(s) - lithium tantalate , stoichiometry , tantalate , curie temperature , lithium (medication) , materials science , analytical chemistry (journal) , crystal (programming language) , lattice constant , single crystal , crystallography , mineralogy , chemistry , diffraction , ferroelectricity , lithium niobate , condensed matter physics , optics , medicine , optoelectronics , endocrinology , computer science , dielectric , programming language , physics , chromatography , ferromagnetism
Accurate lattice parameter, hydrostatic density and Curie temperature measurements have been made on lithium tantalate single crystals grown from different melt compositions. Crystal compositions were determined by comparing crystal Curie temperatures with those determined from well reacted ceramic specimens of known composition. These measurements showed that a stoichiometric melt produces nonstoichiometric crystals and that the congruently melting composition is 49.0 mole % Li 2 O. The resulting defect model for nonstoichiometric lithium tantalate is Li[1−(5− n ) x ]Ta(1+ x ) nxe − O 3 where n ≃2 and the existence region is 46.0 to 50.4 mole % Li 2 O at room temperature.