Structural integrity and characteristics at lattice and nanometre levels of ZrN polycrystalline irradiated by 4 MeV Au ions

We report an as-hot-pressed zirconium nitride polycrystalline with its primary crystal structure maintained no change but lattice defects and features were introduced at nanometre-scale after being irradiated by 4 MeV Au2+ with a total fluence of 5 × 1016/cm2. The variation of grey-level seen in backscattered electron images and electron backscattered diffraction maps directly evidenced the structure integrity of the polycrystalline ZrN is well maintained with no crystal structure change of ZrN. The irradiation depth had no relevance to crystal orientation, and Au deposition peaked at a depth of ∼0.58 μm with a near-Gaussian distribution. Within a depth <0.58 μm, long dislocation lines were developed with a Burgers vector of [01¯]b/2 and density 3.2 × 1014 1/m2; beyond this depth, dislocation loops were formed with much higher density. In the ionization zone, cubic ZrO2 crystallites precipitated in a size of ∼5 nm. The irradiation damage processes are discussed based on the observed features.