A high-resolution electron microscopic study was made of a sintered β-phase specimen which had been neutron-irradiated to a dose of 2.8 x 1026/m2 (E > 0.1MeV) at 793K. The Burgers vector of the neutron-induced interstitial dislocation loops was found to be about 1/6<023>, and corresponded to an extra layer of SiN4 tetrahedra which was inserted into {10•0} planes.

A Structural Model of Defects in β-Si3N4 Produced by Neutron Irradiation. M.Akiyoshi, T.Yano, M.L.Jenkins: Philosophical Magazine A, 2001, 81[3], 683-97