Berlin 2005 – scientific programme

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DF: Dielektrische Festkörper

DF 8: Gl
äser II (gemeinsam mit FV DY)

DF 8.4: Talk

Monday, March 7, 2005, 15:00–15:15, TU A060

Reaction-Diffusion in Glasses — •Knud Zabrocki and Steffen Trimper — Fachbereich Physik, Martin-Luther-Universität, Friedemann-Bach-Platz, 06108 Halle

The formalism of reaction-diffusion rate equations is applied to an experimental measured phenomenon of particle creation in glasses. The description of the kinetic growth is major task of our investigation. There are three partial processes, which are proceeding in parallel: (i) Reduction of silver ions to silver atoms; (ii)Nucleation of the silver atoms; (iii) Creation of silver particles. Most of the known theoretical models are using homogeneous distribution of the silver ions in the first step. In our case we take a possible mobility of the silver ions into account resulting in a system of partial differential equation instead of ordinary ones. Whereas an effective linear theory is solved exactly in form of Fourier series, the complete non-linear system of equations is performed numerically. After the implementation of the other two steps of the kinetics, first in sequential manner and then in a parallel one we find the spatial distribution of the silver particles as well as the size distribution of them which influence the macroscopic properties of the glass like the colour and the rigidity.