SOLID-SOLUTIONS OF METASTABLE TETRAGONAL ZRO2 AND CE3ZRO8 IN THE SYSTEM ZRO2-CEO2

In the system ZrO2-CeO2, metastable t-ZrO2 solid solutions containing up to 30 mol % CeO2 crystallize at temperatures of 385-430 degrees C f rom amorphous materials prepared by the hydrazine method. Crystalline Ce3ZrO8 solid solutions are formed in as-prepared powders between 30-7 5 mol % CeO2. The variation of the lattice parameters of both solid so lutions is determined as a function of CeO2 content. The value of the lattice parameter of pure Ce3ZrO8 (cubic) is a = 0.5342 nm. Detailed c haracterization of the Ce3ZrO8 powder has been performed. Crystallite size and particle size are strongly dependent on the heating temperatu re. Specific surface areas do not drop below 40 m(2) g(-1) until the h eating temperature is above 1000 degrees C.