Ss. Jiang et al., SYNTHESIS OF YTTRIA-STABILIZED ZIRCONIA NANOPARTICLES BY DECOMPOSITION OF METAL NITRATES COATED ON CARBON POWDER, Journal of materials research, 11(9), 1996, pp. 2318-2324
Weakly agglomerated nanoparticles of yttria-stabilized zirconia (YSZ)
were synthesized by a novel process which involved the decomposition o
f metal nitrates that had been coated on ultrafine carbon black powder
, after which the carbon black was gasified. The use of ultrafine, hig
h-surface-area carbon black powder apparently allowed the nanocrystall
ine oxide particles to form and remain separate from each other, after
which the carbon black was gasified at a somewhat higher temperature.
As a result, the degree of agglomeration was shown to be relatively l
ow. The average crystallite size and the specific surface area of the
as-synthesized YSZ nanoparticles were 5-6 nm and 130 m(2)/g, respectiv
ely, for powder synthesized at 650 degrees C. The as-synthesized YSZ n
anoparticles had a light brown color and were translucent, which diffe
rs distinctly from conventional YSZ particles which are typically whit
e and opaque. The mechanism of the synthesis process was investigated,
and indicated that the gasification temperature had a direct effect o
n the crystallite size of the as-synthesized YSZ nanoparticles. High-d
ensity and ultrafine-grained YSZ ceramic articles were prepared by fas
t-firing, using a dwell temperature of 1250 degrees C and a dwell time
of two minutes or less.