Sinyakina S. Evolution of the system ZrO2 - 3 мол. % Y2O3 nanopowders structure under high pressure and temperature conditions

The work is devoted to the investigation of the P–T and T–P- modifications influence on the structure evolution of the amorphous xerogel hydroxide system of of Zr0.97Y0.03 О(OH)2  nH2O. The mechanisms of response of amorphous xerogel nanoparticles system to the impact of pressure in the framework of P–T-modifications have been investigated and determined. It is made possible to explain observed effects of nanoparticle compacts destruction and nonmonotonic change in wettability of the surface fractures of these compacts under 600 MPa. The change in the surface state of an amorphous xerogel after pressure action has been considered and was shown that in modified xerogels the connectivity degree of an aqueous component with the nanoparticles surface was enhanced that lead to a reorganization of the xerogel structure. The dehydration and crystallization mechanisms of xerogel nanoparticles modified under HHP conditions was studied and described. It was shown that the using of serial P–T-modification in zirconia synthesis technology by chemical precipitation method allows to control the morphology and nature of active centers on the surface of oxide nanoparticles.