Premium
Characterization of Alkoxy‐Derived Yttria‐Stabilized Hafnia
Author(s) -
BROWN L. M.,
MAZDIYASNI K. S.
Publication year - 1970
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.1151-2916.1970.tb15978.x
Subject(s) - hafnia , materials science , yttria stabilized zirconia , analytical chemistry (journal) , yttrium , monoclinic crystal system , microstructure , tetragonal crystal system , sintering , mineralogy , scanning electron microscope , crystallography , cubic zirconia , metallurgy , crystal structure , ceramic , chemistry , composite material , oxide , chromatography
High‐purity submicron HfO 2 −Y 2 O 3 powders were prepared by the simultaneous hydrolytic decomposition of hafnium and yttrium alkoxides. Compositions of 1 to 7 mol% Y 2 O 3 in HfO 2 were studied by high‐temperature X‐ray diffraction, electron microscopy, BET surface area measurements, emission spectrographic analysis, TGA, and DTA. X‐ray diffraction and atomic absorption were used to determine the Y 2 O 3 concentration. Hot‐pressing or cold‐pressing and sintering of the powders resulted in nearly theoretically dense bodies with uniform microstructure containing grains 1 to 5 μm in size. Surface reflection ir spectra were obtained for monoclinic, tetragonal, and cubic specimens. Fully cubic HfO 2 with 7 mol% Y 2 O 3 additions was obtained at a relatively low temperature. The hot‐pressed specimens, initially slightly oxygen‐deficient or gray HfO 2‐ x , were reoxidized at 1000°C with no deleterious effects; thin sections were translucent to incident light.