The Enhancement of Diffusion Processes in BCC Phases of Anomalous Metals by Fluctuation-Induced Frenkel Pairs

摘要

The model proposed by A. Seeger and associated with the anomalous enhancement of diffusion processes (DP) by fluctuation-induced Frenkel pairs at phase transformations is evolved and applied in order to explain and discuss a low-temperature curvature of Arrhenius plot for the BCC phases of anomalous metals (AM). By analogy with the consideration of radiation-enhanced diffusion (RED) the analysis of basic kinetic equations solutions as applied to "fluctuation-enhanced" diffusion (FED) processes is carried out. The approximate solutions for the different stages of the fluctuation-induced defects annealing are advanced. The tentative estimations of the FED activation energy Q_(FED)~* and some critical temperature of commencement FED T_(FED) are performed by experimental data handling for β-Zr, β-Ti, γ-U, ε-Pu, β-ZrNb and β-ZrTi alloys. The enhancement parameter of FED R_(FED) = D_(FED) / D_(TAD) is proposed and evaluated for AM. The correlation of both Q_(FED)~*, T_(FED) and R_(FED) with the phase transformation temperature T_(tr) is found.