Evaluation of crystallinity and surface area measurements of plutonium dioxide samples

Plutonium dioxide samples, prepared from plutonium oxalate, plutonium nitrate and plutonium sulphate, were heated at temperatures from 500 to 900°C, under standard conditions, and were examined by X-ray diffraction in silica capillaries of similar diameter at room temperature. The breadth of the diffraction lines was measured by a microdensitometer. Various parameters like crystallite size, shape of the crystallites and surface area per unit mass were deduced. The crystallites were found to grow in size as the oxides were heated to progressively higher temperatures, and the surface area per unit mass decrease with the increase in size of the crystallites. The surface area values were higher for oxides which were prepared by the decomposition of oxalates than for those prepared from nitrate or sulphate.