AVS 51st International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP34
Anomalous Diffusion Permeability of an Interphase Interface in Mo-Ni System Under High-Energy Electron Irradiation

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: G.G. Bondarenko, Moscow Institute of Electronics and Mathematics (Technical University), Moscow, Russia
Authors: G.G. Bondarenko, Moscow Institute of Electronics and Mathematics (Technical University), Moscow, Russia
M.M. Yakunkim, Moscow Institute of Electronics and Mathematics (Technical University), Moscow, Russia
A.V. Artamonov, Moscow Institute of Electronics and Mathematics (Technical University), Moscow, Russia
S.P. Ostashkin, Russian State University of Innovational Technologies and Management, Moscow, Russia
Correspondent: Click to Email
Some of the problems of the theory of transport in solids are anomalous atomic mobility and deviations from the equilibrium concentrations at an interphase interface caused by high-energy irradiation. The problem of anomalous mass transfer of components during long-term electron irradiation can be solved using information on phase diagrams. We study the Mo-Ni system during electron irradiation over the time it takes for stationary state to be achieved and compare the states obtained with equilibrium states. Samples in form of two-layer plates 0.05 (Mo) and 1.5 mm (Ni) in thickness were irradiated in a linear electron accelerator at energies of E = 2-8 MeV in steps of 2 MeV for the time it took for equilibrium structures to be formed. Irradiation was carried out in a special temperature-controlled chamber at 1000 K. The isothermal section of this system at E = 0 was preliminary obtained. Isothermal sections of the phase diagram at various values of E were constructed from the data of phase analysis. We found that the quasi-equilibrium irradiated diffusion zone at the interface is a nanoregion ~20 nm in size. The concentrations of components at the interphase interface significantly change during irradiation. As a result of electron irradiation, the maximum nickel content in the @delta@-phase increases by 12%, the nickel concentration in the molybdenum-based solid solution at the interface increases by a factor of almost four and is equal to ~10% at E = 8 MeV. Changes in the component concentrations at interphase interfaces can be described without applying thermodynamics by introducing the concept of the diffusion permeability of an interphase interface. Given the appearance of a phase diagram at various values of E, it is possible to calculate the diffusion permeability of the interface for all cases. This approach was used to account for the concentration deviations detected at the interphase interface during high-energy electron irradiation.