Polygonization of single crystals of the fluorite-type oxide UO(2) due to high dose ion implantation
Above a certain level of damage on fission products, UO(2) grains are seen to subdivide into 1.0 E4 - 1.0 E5 subgrains (RIM effect). A parametric study with UO(2) single crystals and in situ ion implantation/channelling analysis was performed to investigate the basic mechanisms of this phenomenon. For most experiments, Xe-ions of up to 300 keV energy and up to doses of 1.0 E17 ions/cm2 were used. At a given critical dose, dramatic changes of the damage peak in the channelling spectra were seen. Though these peaks eventually reached the random yield, analysis of the peak shapes in X-ray diffraction measurements (Omega scans) and channelling angular scan measurements proved that polygonisation (rather than amorphisation) had occurred, causing a fine-grained polycrystalline structure with a misalignment between grains of a few degrees only. The mechanism of this process is discussed in terms of overpressurised gas bubbles causing microfractures and its relevance to the technological application is also considered.
Bibliographic Reference: Paper presented: 7th International Conference on Radiation Effects in Insulators (REI-7), Nagoya (JP), September 6-10, 1993
Availability: Available from (1) as Paper EN 37878 ORA
Record Number: 199311355 / Last updated on: 1994-11-28
Original language: en
Available languages: en