Mechanical mixtures containing zirconia xerogel and increasing amount of crystalline yttria up to 40 mol%, were hydrothermally treated by microwave route at 110°C for 2 h. All the treatments were performed in the presence of (KOH+K2CO3) mineralizer solution at concentration 0.2 M. Amorphous and hydrated ZrO2–Y2O3 solid solutions with yttria content up to 33.3 mol% (corresponding to Zr/Y molar ratio equal to 1), resulted after the hydrothermal treatments. A remarkable reduction of the surface area has been detected at increasing yttria content of the amorphous phases with a corresponding increase of the exothermic peak of crystallization. A mechanism of reaction for the formation of the amorphous solid solutions has been proposed.
Microwave-hydrothermal treatment of mechanical mixtures of ZrO2 xerogel and crystalline Y2O3
DELL'AGLI, Gianfranco;MASCOLO, Giuseppe;MASCOLO, Maria Cristina;
2005-01-01
Abstract
Mechanical mixtures containing zirconia xerogel and increasing amount of crystalline yttria up to 40 mol%, were hydrothermally treated by microwave route at 110°C for 2 h. All the treatments were performed in the presence of (KOH+K2CO3) mineralizer solution at concentration 0.2 M. Amorphous and hydrated ZrO2–Y2O3 solid solutions with yttria content up to 33.3 mol% (corresponding to Zr/Y molar ratio equal to 1), resulted after the hydrothermal treatments. A remarkable reduction of the surface area has been detected at increasing yttria content of the amorphous phases with a corresponding increase of the exothermic peak of crystallization. A mechanism of reaction for the formation of the amorphous solid solutions has been proposed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
