Predicting and Controlling Materials Properties in the Nano-Scale

Featuring:

Professor C. H. Woo
Department of Electronic and Information Engineering
Hong Kong Polytechnic University

Location: CS 174

Abstract:

Physical understanding is important for the prediction and control of materials properties, especially those under extreme operating conditions, such as high stress, high strain rate, extreme dimensions, high radiation field, etc. This talk concentrates on our work on predicting and controlling materials properties in the nano-scale. Thus, the successful incorporation of components of nano-scale into a working device depends on a thorough understanding of the dependence of the functional relationship between properties of the nano-component and environmental variables, such as ambient temperature and applied load, on the component size.  This is particularly important for many applications of functional materials in the thin film form, such as ferromagnetics, ferroelectrics, piezoelectrics, shape-memory alloys, liquid crystals, etc., in which property changes due to phase transitions is crucial to their usefulness. Characteristics of nano-materials may be very sensitive to the sample dimensions, due to the large surface-to-volume ratio and the small dimension, particularly their phase stability.  This sensitivity is both a source of concern and opportunities for the design and optimization of the fabrication process, performance and reliability of the associated products. Due to the complexity of the phase transition problem, resulting from its non-linear nature, a holistic and thorough understanding of the complex interplay of relations among the many important factors, such as film thickness, ambient temperature, constraint of the substrate, surface relaxation, order and direction of the transition, etc., has yet to be completed, despite decades of research work.  

About the Speaker:

Professor Woo graduated from The University of Hong Kong in Applied Math, got his Ph.D. in Theoretical Solid-State Physics from Univ. of Waterloo, Canada, and was awarded the D.Sc. degree from his Alma Mater in recognition of his contribution in materials science and engineering.   Professor Woo joined Atomic Energy of Canada right after his PhD, attained the highest scientific rank before joining The Hong Kong Polytechnic University in 1996.  While with AECL, Prof. Woo was also Adjunct Professor of Physics with the University of Manitoba. He is currently Chair Professor of Solid-State Electronics of PolyU where he has formerly held the Chair of Mechanical Engineering. Professor Woo’s interests cover many areas of theoretical condense-mater physics including irradiation damage theory, nano-plasticity and thin film materials.