RELATIONSHIP BETWEEN THE SURFACE-AREA AND THE X-RAY CRYSTALLITE SIZE FOR THORIUM-OXIDES

The present results confirm the surface area-crystallite size relationship that Allred, Buxton, and McBride [J. Phys. Chem. 61, 117 (1957)] obtained for thoria derived from oxalate decomposition and extend the applicability of their equation to other thoria samples. It was observed that the presence of the nitrate ion (or oxides of nitrogen) during the oxalate decomposition strongly influenced the surface area (crystallite size) of the final product. The precipitation procedure appears to determine the crystallite size for thoria from the decomposition of the hydroxide.". © 1979."