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Defect Characterization in and Precipitation from CaO:Yb 2 O 3 Crystalline Solutions
Author(s) -
BARRY THOMAS L.,
ROY RUSTUM
Publication year - 1967
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.1151-2916.1967.tb15050.x
Subject(s) - diffusion , ion , precipitation , activation energy , materials science , characterization (materials science) , kinetics , decomposition , kinetic energy , mineralogy , chemical engineering , chemistry , thermodynamics , nanotechnology , physics , organic chemistry , quantum mechanics , meteorology , engineering
The defects formed when trivalent rare earth ions are accepted into the sodium chloride structure of CaO were determined from precise measurement of lattice parameters and densities to be predominantly cation vacancies. The exsolution kinetics of Yb 2 O 3 from CaO crystalline solutions were studied in situ using high‐temperature X‐ray methods. Kinetic plots for this reaction show that it is diffusion‐controlled, at least in the initial stages. Quantitative information could not easily be extracted from the results of this study because of the appearance of a reaction intermediate. The appearance of this intermediate is rationalized by depicting the free energy‐composition relations which exist at the decomposition temperatures used.