Extremely Suppressed Grain Growth of Y[sub 2]O[sub 3]-Stabilized Zirconia Nanocrystals Synthesized by the Nonhydrolytic Sol–Gel Technique

Yttria-stabilized zirconia (YSZ) nanocrystals (NCs) have been synthesized by a nonhydrolytic sol–gel technique using the alkyl halide elimination reaction between the zirconium and yttrium isopropoxides and zirconium chloride in the oleylamine at 340 ° C . The grain growth behavior during heating of the agglomerated NCs up to 1000 ° C of the resulting NCs was studied under O 2 atmosphere. Colloidal solutions of well-crystallized YSZ NCs, whose average size was approximately 3 nm , were successfully obtained for various yttria concentration, x in ( Zr 1 − x Y x ) O 2 − δ , of 0 < x < 0.34 . For the ( Zr 0.85 Y 0.15 ) O 2 − δ NCs, no distinct grain growth was observed below 700 ° C , and their average grain size was suppressed to 5 – 8 nm even when heating at 800 ° C . As compared with the YSZ NCs synthesized by the aqueous solution technique, whose grains grew to at least 15 nm in size when heated at 800 ° C , the present nonhydrolytic sol–gel technique resulted in NCs possessing an extremely suppressed grain growth characteristic. The suppressed grain growth was related to the hydroxyl defect-free nature and high crystallinity of the YSZ NCs synthesized by the nonhydrolytic sol–gel technique, in contrast to the aqueous solution technique, which results in amorphous complex oxyhydroxides.