Stochastic Dynamics Of Crystal Defects

Stochastic Dynamics of Crystal Defects

This thesis is concerned with establishing a rigorous, modern theory of the stochastic and dissipative forces on crystal defects, which remain poorly understood despite their importance in any temperature dependent micro-structural process such as the ductile to brittle transition or irradiation damage. The author first uses novel molecular dynamics simulations to parameterise an efficient, stochastic and discrete dislocation model that allows access to experimental time and length scales. Simulated trajectories are in excellent agreement with experiment. The author also applies modern methods of multiscale analysis to extract novel bounds on the transport properties of these many body systems. Despite their successes in coarse graining, existing theories are found unable to explain stochastic defect dynamics. To resolve this, the author defines crystal defects through projection operators, without any recourse to elasticity. By rigorous dimensional reduction, explicit analytical forms are derived for the stochastic forces acting on crystal defects, allowing new quantitative insight into the role of thermal fluctuations in crystal plasticity.

Dynamics of Systems on the Nanoscale

This book presents the structure formation and dynamics of animate and inanimate matter on the nanometre scale. This is a new interdisciplinary field known as Meso-Bio-Nano (MBN) science that lies at the intersection of physics, chemistry, biology and material science. Special attention in the book is devoted to investigations of the structure, properties and dynamics of complex MBN systems by means of photonic, electronic, heavy particle and atomic collisions. This includes problems of fusion and fission, fragmentation, surfaces and interfaces, reactivity, nanoscale phase and morphological transitions, irradiation-driven transformations of complex molecular systems, collective electron excitations, radiation damage and biodamage, channeling phenomena and many more. Emphasis in the book is placed on the theoretical and computational physics research advances in these areas and related state-of-the-art experiments. Particular attention in the book is devoted to the utilization of advanced computational techniques and high-performance computing in studies of the dynamics of systems.

Catalog of National Bureau of Standards Publications, 1966-1976