Dresden 2006 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 46: Poster
DY 46.103: Poster
Donnerstag, 30. März 2006, 16:00–18:00, P1
KMC simulations of thermally sintering nano-clusters in 3D — •Martin Fendrich, Ruslan Zinetullin, Frank Westerhoff, and Dietrich E. Wolf — Institut der Physik, Universität Duisburg-Essen, Campus Duisburg, Germany
A C++ code is developed in order to simulate the thermal sintering process of nano-particles using the kinetic Monte-Carlo method (KMC). For the sintering time of two different sized particles we obtained the power law τ ∝ R4 with the reduced radius (R1−1+R2−1)−1, which means that the relaxation time is dominated by the smaller particle. We proved the existence of a capillary instability of crystalline nano-wires having a length-to-width ratio of 8.8 of the resulting fragments. The time needed for separation of the wires turned out to be ∝ R4± 0.2. By letting two independent fcc-lattices interpenetrate each other and allowing atoms to exchange between them, a grain boundary is modeled. We developed a hybrid simulation scheme combining the atomistic KMC method with a numerical integration of the equations of motion for two particles in contact. The qualitative sintering process may be divided into two stages. A fast reorientation of the grains takes place leading to special classes of mutual torsions with misorientation angles between 0 and ≈ 80∘. These classes can be understood in terms of a coherent site lattice analysis. This is followed by a long coalescence stage.