Radiation damage and recovery due to the interaction of crystal defects with anharmonic lattice excitations

In the present paper we consider mechanisms of recovery from radiation damage, based on the radiation-induced formation of highly localized and very persistent anharmonic lattice excitations (called alternatively Intrinsic Localized Modes, Discrete Breathers or Quodons) that propagate great distances in atomic-chain directions and interact with crystal defects such as voids and dislocations. The rate theory of microstructure evolution in solids is modified with account of quodon-induced production of Schottky defects and is applied for description of the low-temperature radiation-induced “annealing” of voids. The quodon propagation length deduced from comparison of the model with experimental data appears to be within the micron range, which is consistent with independent data on the irradiation-induced diffusion of interstitial ions in austenitic stainless steel. Experimental evidence of larger quodon ranges obtained recently for copper is also discussed along with some other manifestations of the quodon interaction with extended defects.