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Preparation of High‐Density Ceria‐Yttria Ceramics
Author(s) -
DRAGOO A.L.,
DOMINGUES L. P.
Publication year - 1982
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.1151-2916.1982.tb10428.x
Subject(s) - materials science , coprecipitation , calcination , ceramic , yttria stabilized zirconia , oxide , ammonium hydroxide , inorganic chemistry , chemical engineering , mineralogy , cubic zirconia , metallurgy , chemistry , biochemistry , engineering , catalysis
Fine Ce‐Y oxide powders were prepared by coprecipitation of the carbonate, followed by calcination at 620°C. Hydrolysis of trichloroacetic acid was used to precipitate most of the material from a homogeneous solution; addition of ammonium bicarbonate and ripening of the precipitate were used to increase the yield to 68 to 70%. The precipitate apparently consisted of more than one phase and had an overall composition which suggested that it was a possible mixture of hydrated carbonate, hydroxycarbonate, and hydroxide. The calcined oxide powder was used to prepare an yttria‐doped ceria ceramic by hot‐pressing. The ceramic had the fluorite structure phase with a lattice constant of 0.541088 nm and a composition of Ce 0.914 Y 0.086 O 1.957 . The bulk density of the material was 6.96 g/cm 3 , or 99.4% of theoretical density. The ceramic had equiaxed grains, with an average dimension of 1 to 4 μm and with residual porosity mainly along the grain boundaries. Ac impedance properties of the chemically prepared oxide are compared with those of mechanically mixed and fired Y‐doped CeOZ.