cfaed Seminar Series

cfaed Seminar Series

Prof. Dr. Ken Elder , Oakland University, Department of Physics

Honeycomb and Triangular Domain Wall Networks in Heteroepitaxial Systems

09.03.2016 (Wednesday) , 17:00 - 18:00
TUD Mathematics (WIL C 307) , Willersbau, Zellescher Weg 12-14 , 01069 Dresden

Please be kindly invited to this talk within the series Dresdner Mathematisches Seminar, organized jointly by the Dresden Center for Computational Materials Science (DCMS).

In this talk I would like to present a study of the influence of misfit strain, adhesion strength, and lattice symmetry on the complex Moire patterns that form in ultrathin films adsorbed on compact triangular surfaces, such as graphene on metals. The approach here is based on a complex Ginzburg-Landau model of the film that incorporates elastic strain energy and dislocations. The results indicate that the different symmetries of the heteroepitaxial systems lead to distinct type of domain wall networks and phase transitions among various surface Moire patterns and superstructures. In addition, one of the commensurate-incommensurate phase transitions is observed to change from continuous to discontinuous at large strains, indicationg a breakdown of continuum approaches at large strains due to the discreteness of the film lattice.

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