Dresden 2009 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 26: Poster II
DY 26.3: Poster
Thursday, March 26, 2009, 16:00–18:00, P1A
Monte-Carlo-Simulations of ionic diffusion dynamics in ordered and disordered materials — •Patrick Mexner1, André Schirmeisen1, and Andreas Heuer2 — 1Institute of Physics, University of Muenster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany — 2Institute of Physical Chemistry, University of Muenster, 48149 Muenster, Germany
Motivated by the successful measurement of ionic diffusion dynamics in nanoscopic volumes of a Lithium-Silicate-Glass by time domain electrostatic force spectroscopy (TD-EFS) [1], we simulate elementary ion hopping processes in Monte-Carlo-Simulations (MCS). The TD-EFS method measures the time evolution of the force between the tip of an atomic force microscope and the ion conducting sample after a tip voltage is applied. In our model we consider the influence of different site-energies and energy distributions in ion conductors, as well as temperature and particle concentrations on simulated relaxation processes. By variation of parameters we model both crystalline and disordered phases and compare them with experimental data. Our MCS is able to model cubic systems of 5-10nm length which is in the order of estimated effective volumes for tip-sample interaction of approx. 50 cubic nm. Hence it enables us to directly relate simulated and experimental data for a better understanding of elementary ion jumps under the influence of electric fields.
[1] Schirmeisen et al., Phys. Rev. Lett. 98 (2007) 225901