Hydrothermal syntesis of nanocrystalline powders in the ZrO2-Y2O3-CeO2 system

A.Shevchenko,
   
V.Vereschaka,
  
L.Lopato
 

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Krzhizhanovsky str., 3, Kyiv, 03142, Ukraine
Powder Metallurgy, 2007, #1/2
http://www.materials.kiev.ua/article/280

Abstract

The properties of nanocrystalline powder of composition (mol. %) 95 ZrO2 - 2 CeO2 - 3Y2O3, synthesized with the complex way of coprecipitation and hydrothermal decomposition were investigated. Is was found, that after coprecipitation the X-ray amorphous gel was formed, which consists of hard agglomerates from 5 to 10 microns. The gel specific surface area was 120 m2/g, bottle density was 2,94 g/sm3. The low-temperature metastable cubic solid solution based on ZrO2 (F- ZrO2) was formed after hydrothermal synthesis. The specific surface area was 101,6 m2/g,bottle density was 4,65 g/sm3. "Soft" agglomerates ( 0,5 - 10 microns) consist of the primary particles, size 10 nm. Varying the technological steps for processing of hydrothermal suspension results in shaping of "soft" agglomerates with branched internal porosity. The method allows to synthesize the powders of necessary compositions in the ZrO2-CeO2-Y2O3 system .