ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

Student projects

Research Group Scalebridging Simulation of Functional Composites

If you are interested in a student research project in the group Scalebridging Simulation of Functional Composites please contact Dr. Anna Grünebohm.

  1. Student project/master thesis: Functional responses of ferroelectric composites: an ab initio based study on interface strain

    In this project we investigate the impact of interface strain on the functional responses of ferroelectric composites.

    Ferroelectric perovskites are widely used in applications and are promising for energy harvesting as well as for future efficient solid-state cooling devices. All applications share the following demands on materials design: Replace toxic Pb and increase efficiency of the functional responses in a broad and suitable operation range. In this quest, ferroelectric composites came into focus as they can be optimized by the choice of different constituents and their morphologies.

    Recently we have shown how one may optimize the electrocaloric response of BaTiO3 films by biaxial strain in the (001)-plane. Thereby the domain structure of the film plays a crucial role. The task of this project is to extend this study to different crystallographic directions and solid solutions of (Ba,Sr)TiO3. We will explore the temperature-strain phase diagrams of and the stability of specific elastic domain structures. For this purpose we will perform coarse-grained molecular dynamics simulations employing the feram code.

    Contact: Dr. Anna Grünebohm. Email: anna.gruenebohm@rub.de

  2. Student project/master thesis: Phase stability of BaTiO3 under non-collinear electrical fields

    The focus of this project is the coupling between structural phases of (Ba,Sr)TiO3 and applied electrical fields. Ferroelectric perovskites based on BaTiO3 are widely used in applications and are promising for energy harvesting as well as for future efficient solid-state cooling devices. All applications share the following demands on materials design: Replace toxic Pb and increase efficiency of the functional responses in a broad and suitable operation range. In particular phase transitions between different structural phases allow for giant responses. Without an applied field cubic BaTiO3 undergoes three phase transitions to tetragonal, orthorhombic and finally to the rhombohedral phase. It has been shown in literature that an external field may strongly modify these transitions.

     

     

    In this project we will study the impact of different field directions. In particular we will explore the temperature-field phase diagrams of (Ba,Sr)TiO3 solid solutions for monoclinic electrical fields. For this purpose we will perform coarse-grained molecular dynamics simulations employing the feram code.

    Contact: Dr. Anna Grünebohm. Email: anna.gruenebohm@rub.de

  3. Other student projects (e.g. atomistic simulations of the electro caloric effect, DFT and MC study of the complex magnetic structure of Mn-based Heusler alloys) are available upon request, for more information please contact Dr. Anna Grünebohm or Dr. Ruben Khachaturayan.