Regensburg 2022 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 3: Statistical Physics far from Thermal Equilibrium

DY 3.6: Vortrag

Montag, 5. September 2022, 11:30–11:45, H18

Modeling flash sintering conditions with Boltzmann equations — •Magdulin Dwedari, Lothar Brendel, and Dietrich Wolf — University of Duisburg-Essen, Lotharstraße 1, 47057 Duisburg

In a flash sintering experiment, a suitable combination of electric field and furnace heating is applied to the sample, which makes it possible to sinter it in a matter of seconds and at significantly lower temperatures compared to conventional sintering. An established hypothesis that explains the key signatures of a flash sintering event, such as a surge in conductivity, is that the electric field causes a rapid generation of Frenkel defects in the sample. With molecular dynamic simulations it has been confirmed that a phonon proliferation at the Brioullin-Zone edge can cause a Frenkel defect concentration 10¹⁵ times higher than the thermal concentration.
To study the effects of an electric field on the phonon distribution, we model the electron system governed by an electric field and the phonon system coupled to an external heat bath with two coupled Boltzmann equations. The key difference to previous work exciting the electron system via a laser pulse is that our excitation term models the effects of the electric field and is therefore continuous and imposes a cylindrical symmetry.