High-purity samples were neutron-irradiated (E > 0.1MeV) in a fast reactor, to up to 4.2 x 1026/m2 at 650 to 1008K. Changes in the macroscopic length and lattice parameter were measured. The macroscopic swelling was observed to amount to between 1.82 and 2.1%. The change in the lattice parameter was also very small, when compared with the macroscopic length change. The a-axis expanded very slightly, while the c-axis contracted. The formation of a high density of interstitial dislocation loops on the basal plane was observed.

Neutron Irradiation Damage in Aluminium Oxide and Nitride Ceramics up to a Fluence of 4.2 x1026/m2. T.Yano, K.Ichikawa, M.Akiyoshi, Y.Tachi: Journal of Nuclear Materials, 2000, 283-287, 947-51