Naslov
Influence of pH on the stability of low temperature t-ZrO2

Autori
Štefanić, Goran ; Musić, Svetozar ; Gržeta, Biserka ; Popović, Stanko ; Sekulić, Andreja

Izvornik
Journal of physics and chemistry of solids (0022-3697) 59 (1998), 6-7; 879-885

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Sažetak
The influence of the conditions of the chemical synthesis on stability of metastable t-ZrO2 was studied. Zirconia samples were crystallized from zirconium hydroxide precipitated at pH 13, 7 and 2.5. In all the samples, t-ZrO2 was the dominant phase but the m-ZrO2 phase was also present as a minor component. The obtained samples were subjected to the influence of temperature (500 and 700 oC), pressure (500, 1000 and 1350 MPa) and g-irradiation (10 MGy). The results of phase analysis showed that the change in the pH of zirconium hydroxide precipitation significantly changed the sensitivity of the metastable t-ZrO2 to temperature and pressure. The metastable t-ZrO2 was the most stable in the sample obtained from zirconium hydroxide precipitated at pH 2.5 (a decrease of 2% of the starting t-ZrO2 phase after heating at 700 oC and a decrease of 35% after the application of the pressure of 1350 MPa) and the most unstable in the sample obtained from zirconium hydroxide precipitated at pH 7 (a decrease of 97 % of the starting t-ZrO2 phase after heating at 700 oC, and a decrease of 65% after application of the pressure of 1350 MPa). The effects of the factors mentioned were monitored by X-ray powder diffraction and laser Raman spectroscopy. The results of laser Raman spectroscopy indicated that, without regard to the precipitation pH, g-irradiation had very small influence on the metastable t-ZrO2.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA