Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 77: Oxides and insulators: Epitaxy and growth

O 77.12: Vortrag

Donnerstag, 25. März 2010, 17:45–18:00, H42

Title: Simulation of deposition and growth of Xe-crystals via the low-temperature atom beam deposition method — •Nicola Toto, Christian Schoen, and Martin Jansen — Max Planck Institute for Solid State Research - Heisenbergstrasse, 1 - 70569 Stuttgart - Germany

We model the deposition of Xe-atoms on a sapphire substrate and the subsequent growth of ordered Xe-phases via the low-temperature atom beam deposition method. This chemical synthesis method (D. Fischer and M. Jansen, J. Am. Chem. Soc. 41, 1755 (2002)) is a successful new way to synthesize metastable solid compounds. The modeling procedure consists of several steps, where we use empirical potentials to model the interactions within the substrate, the Xe-Xe-interactions in the gas phase and the solid, and the interactions between the Xe-atoms and the substrate. In a first step, we established that under the experimental conditions, no Xe-clusters form in the gas phase, and thus the deposition could be described by the adsorption of single Xe-atoms on the substrate at low temperatures. Next, we simulate the Xe deposition process and we study the growth mode depending on various synthesis parameters such as the deposition rate and the temperature of the substrate. Finally, the deposited Xe-layers are annealed, and the structure of the resulting compound is analyzed. We studied the establishment of locally ordered regions as a function of time, both during the deposition and the annealing. We observed that the final configuration is always crystalline, although defects such as stacking faults and dislocations are likely to form.