Defect aggregates in neutron-irradiated β-Si3N4

摘要: Abstract Microstructural analysis of the defect aggregates formed in bulk samples polycrystalline β-Si3N4 neutron-irradiated to a dose ∼2.0 × 1026n/m2 at temperatures 1100 K and 925 has been carried out. This study shown that are faulted dislocation loops lying on {1010} planes with Burgers vector b ≅ 1 /10 . The is non-rational but corresponds insertion an extra layer [SiN4] tetrahedra {10l0} plus additional shear loop plane. formation these dependent upon temperature irradiation. In sample irradiated their additionally whether or not particular grain contains pre-existing c-axis dislocations. If no dislocations present then independent nucleation apparent; if there form from apparent dissociation between arcs irradiation-induced helical di...