Topic: Thermodynamics of liquid and metastable solid alloys

Speaker: Professor Ferdinand Sommer

          Max-Planck-Institut für Metallforschung, Stuttgart, Germany

Time: 10:00-11:30, (Wendesday), Oct. 28th , 2015

Venue: Room 468, Lee Hsun Building, IMR, CAS

Welcome to attend!

Abstract

The experimental methods to obtain reliable thermodynamic data of liquid alloys at constant pressure as a function of composition and temperature will be firstly summerized. In order to evaluate the consistence of the experimentally-determined macroscopic thermodynamic data, a semi-empirical approach to calculate thermodynamic properties of liquid alloys was proposed. Adopting this approach, the thermodynamic properties can be extrapolated into regions of temperature and composition where direct experimental measurements do not exist.

Expressions for the Gibbs energies of interfaces occurring in particular for solid and/or liquid/amorphous metals or alloys in contact with each other have been developed on the basis of the "macroscopic atom" Miedema model, where the entropy contributions of alloys have been derived applying a recently developed formalism. These results provide a thermodynamic basis for unusual phenomena (the aluminium-induced crystallisation of amorphous silicon and the layer exchange occurring in bi-layers of crystalline aluminium and amorphous silicon) observed in nano-sized systems.