Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 31: Computational Materials Modelling - Diffusion & Kinetics II

MM 31.2: Vortrag

Mittwoch, 13. März 2013, 10:30–10:45, H24

A first-principles study of energetics of As, Sb and Bi along selected deformation paths and its application to structure of epitaxial thin films — •Martin Zouhar¹ and Mojmír Šob^1,2,3 — ¹Central European Institute of Technology, CEITEC MU, Brno, Czech Republic — ²Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno, Czech Republic — ³Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic

We present a comprehensive density-functional-theory study of total energy and structural properties of As, Sb and Bi in their A7 ground state and three cubic modifications. All the structures studied are newly described on equal footing with the help of a hexagonal unit cell and can be represented as points in a 3-dimensional parameter space spanned by atomic volume, trigonal distortion and an internal parameter u of the A7 structure (for cubic structures, u=0.25). We calculated the total energies along selected deformation paths by pseudopotential VASP code, displayed them in contour plots as functions of the above-mentioned parameters, identified energy extrema corresponding to the four basic structures and found minimum energy paths connecting selected structures. The calculated energy profiles are employed to determine the structure parameters of As, Sb and Bi thin films on various substrates with the (111) cubic or (0001) hexagonal geometry. Overall good agreement with available experimental data has been found, but we also provide many theoretical predictions which may motivate experimentalists for a deeper study of these systems.