Phenomenological coefficients in solid-state diffusion: an Introduction

In this review, which is intended as an introduction to the subject, we introduce the phenomenological transport coefficients in solid-state diffusion and discuss their structure and physical meaning. Next, we discuss the Darken, the Manning, the Moleko, Allnatt and Allnatt and the Heumann expressions which relate the phenomenological coefficients to the (measurable) tracer diffusion coefficients. Finally, we discuss the relationships (sum-rules) among the phenomenological coefficients themselves in randomly mixed systems and note their applicability for simplifying collective diffusion problems

Carbon Interstitial Diffusion in gamma-Fe

n this paper, we employ a four-frequency model for carbon diffusion in austenite where interstitials can diffuse either as isolated species or pairs. We make use of the Okamura and Allnatt formalism that has recently been shown to be near exact. The general finding of a previous analysis of McKee is confirmed: the increase of both tracer and chemical carbon diffusion coefficients with carbon composition at 1000°C is largely a result of a much higher rate of rotation of an interstitial pair compared with isolated interstitials. However, we find that the carbon atoms move almost two times faster as a rotating pair than found originally by McKee

Computer simulation of the formation of hollow nanocrystals

Experiments on the formation of hollow nanocrystals of cobalt sulphide by way of the Kirkendall effect have been reported recently by Yin et al. We perform a set of Monte Carlo simulations of the process to explore the phenomenon

Recent progress in the simulation of diffusion associated with hollow and Bi-metallic nanoparticles

In this paper, we review the recent understanding gained by kinetic Monte Carlo and molecular dynamics simulation and related theory of the diffusion processes involved in 1) the formation and later shrinkage of hollow nanoparticles and 2) the formation of segregated bi-metallic nanoparticles

Calculation of the effective thermal conductivity in composites using finite element and Monte Carlo Methods

In this paper, the Finite Element and lattice Monte Carlo methods are used to calculate the effective thermal conductivity of two models of a composite: circular and square inclusions arranged in a square planar arrangement. A new lattice Monte Carlo method based around Fick’s First Law is also presented. Excellent agreement is found between these quite different methods. It is also shown that the results are in excellent agreement with the century-old Maxwell Equation

Heat transfer in multi-phase materials

This book provides a profound understanding, which physical processes and mechanisms cause the heat transfer in composite and cellular materials. It shows models for all important classes of composite materials and introduces into the latest advances. The book covers, composite materials (Part I), porous and cellular materials (Part II) and the appearance of a conjoint solid phase and fluid aggregate (Part III)