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Quenched Metastable Glassy and Crystalline Phases in the System Lithium‐Sodium‐Potassium Metaniobate‐Tantalate
Author(s) -
NASSAU KURT,
WANG CHRISTINE A.,
GRASSO MICHAEL
Publication year - 1979
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1979.tb19116.x
Subject(s) - natural bond orbital , differential thermal analysis , materials science , metastability , potassium niobate , lithium (medication) , quenching (fluorescence) , crystallization , phase (matter) , analytical chemistry (journal) , ionic conductivity , ferroelectricity , ternary numeral system , crystallography , ionic bonding , dielectric , ternary operation , mineralogy , chemistry , ion , diffraction , fluorescence , optics , electrolyte , endocrinology , computer science , density functional theory , chromatography , programming language , medicine , physics , computational chemistry , optoelectronics , organic chemistry , electrode
A previous study of the system (Li,Na,K)TaO 3 was extended to include the metaniobates. Glasses were made by twin‐roller‐quenching 33 compositions in the three pseudobinary systems as well as in the pseudoternary system composed of LiNbO 3 , NaNbO 3 , and KNbO 3 and in the pseudobinary M(Nb,Ta)O 3 where M is Li, Na, or K. Glasses were obtained in all but the most Na‐rich regions. Study of these metastable compositions by X‐ray diffraction and differential thermal analysis showed the appearance of four metastable crystalline phases on crystallization, one centered at KNbO 3 , one with an extended occurrence in the ternary system (Li,Na,K)NbO 3 , one centered about Li 0.6 Na 0.4 NbO 3 , and one at KNb 0.25 Ta 0.75 O 3 . There is some evidence for a subsolidus two‐glass region in the system (K,Na)NbO 3 . The ionic conductivity of the LiNbO 3 glass was ∼10 −5 Ω −1 cm −1 and the dielectric constant shows ferroelectricity‐like behavior. Some infrared absorption data gave almost identical curves for the glass and the metastable crystalline phase, which was the first to crystallize.