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MM: Fachverband Metall- und Materialphysik

MM 6: Materials Design II

MM 6.2: Vortrag

Montag, 23. März 2009, 12:15–12:30, IFW D

Structure formation described in terms of General Dynamics instead of Thermodynamics only — •Peter Häussler — Chemnitz University of Technology, Institut of Physics, 09107 Chemnitz

Phase formation is still not well understood. Generally, it is described in terms of thermodynamics under the influence of external parameters as e.g. volume V, temperature T, and concentration x, if alloys are described. Microscopically, by applying quantum mechanics, phase formation is described by Schrödinger’s equation, dealing with internal quantities as the momentum p^→, and/or angular momentum L^→. Subsequently, till the present, there is a gap between both descriptions.

In recent contributions we were able to show that phase formation is strongly dominated by self-organizing resonances between global internal subsystems, causing gaps or pseudogaps at the Fermi energy of the electronic states (Peierls-, Hume-Rothery-like). The self-organization is based on an exchange of momentum and angular momentum, neither described by the present thermodynamics, nor by Schrödinger’s equation as long as Bloch’s theorem can not be applied (as soon the system is still without strict periodicity). We implement the internal effects between global subsystems to a description of phase formation in terms of Gibbs General Dynamics instead of Thermodynamics only. During structure formation, going from the anti-bonding resonant state to the bonding one, entropy is created, allowing the total system to release as much energy as possible.