Growth of beryllium oxide nano-structures during thermal treatment of neutron irradiated beryllium

Beryllium oxide nano-structures grown during high temperature oxidation of neutron irradiated beryllium have been investigated. Oxidation of non-irradiated and neutron irradiated (neutron fluence (3-4) × 10²⁵ m^–2) beryllium was performed in a differential thermal analyzer in an atmosphere of air and its mixture with helium at temperatures up to 1050 °C. Structure of beryllium and its oxide was studied by the means of scanning electron microscopy (SEM). The growth of beryllium oxide nano-structures-“labyrinth type” layers and nano-rods on the inner surfaces of neutron irradiated beryllium was observed by means of SEM. The size of the rods was 10 nm-100 nm in diameter and up to few micrometers in length. There were no or few BeO nano-rods found on the surfaces of non-irradiated pebbles after similar treatment. This indicates that neutron induced irradiation damages, such as dislocation loops, are responsible for the growth of BeO nano-structures.