Reaction-rate theory with account of the crystal anharmonicity

Abstract

Reaction rate theory in solids is modified taking into account intrinsic localized modes or discrete breathers (DBs) that can appear in crystals with sufficient anharmonicity, resulting in violation of Arrhenius' law. Largeamplitude oscillations of atoms about their equilibrium positions in the lattice cause local potentials of alternating sign, which are described in terms of time-periodic modulations of the potential barriers for chemical reactions taking place in the vicinity of DBs. The reaction rate averaged over large macroscopic volumes and times including many DBs is increased by a factor that depends on the DB statistics. The breather statistics in thermal equilibrium and in thermal spikes in solids under irradiation with swift particles is considered, and the corresponding reaction rate amplification factors are derived.

Moving Excitations in Cation Lattices

“…The particular fast kinetics of the reconstructive transformation of muscovite has been related to the existence of transversal breathers or localized nonlinear vibrations [19][20][21]. However, they are not good candidates for quodons, as they move slowly, radiate, and have energies of only a few eV.…”

Supersonic Kinks in Coulomb Lattices

“…Transversal breathers related with the kinetics [4,5,6] have been found in the cation layer, they have small energies below a few eV, move slowly and radiating, therefore they are not good candidates for quodons. We advance the hypothesis that one reason could be that the ion lattice is made out of repulsive cations, K + ions in muscovite.…”

Temperature dependence of irradiation hardening due to dislocation loops and precipitates in RPV steels and model alloys

“…Temperature fluctuations are not the only mechanism of the activation of dislocation unpinning under irradiation, as have been argued by Dubinko et al [40]. The point is that irradiation produces strong lattice excitations (a.k.a.…”