| Popis: |
An anomalous rate minimum exists at about 400 °C for the oxidation of plutonium, i.e., there is a decrease in the oxidation rate as the temperature is increased toward the rate minimum. In situ X-ray diffraction studies have shown that in the temperature region of the rate minimum, there is an increased rate in the formation of PuO. The influence of a PuO surface film on the oxidation of plutonium was investigated with an ellipsometer to determine if a PuO film affects the oxidation rate. Measurements showed that the PuO surface film does retard oxidation at 80 °C. It is further postulated that the anomalous rate minimum for plutonium oxidation near 400 °C results from the increased rate of formation of the protective PuO surface film. |
