Regensburg 2022 – wissenschaftliches Programm

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 8: Crystallography in Materials Science, Microstructure and Dielectric Properties

KFM 8.4: Vortrag

Montag, 5. September 2022, 16:00–16:20, H7

Impact of point defects on the ferroelectric phase diagram: a molecular dynamics study on the defect arrangements — •Sheng-Han Teng and Anna Grünebohm — Interdisciplinary Centre for Advanced Materials Simulation (ICAMS) and Center for Interface-Dominated High Performance Materials (ZGH), Ruhr-University Bochum, Germany

Ferroelectric perovskites usually host imperfections and defects that affect their functional properties. Aging and fatigue are often related to the redistribution of these defects [1-3]. Microscopic insights are therefore needed to better apply these materials to different applications. In this study, we use the first-principle based effective Hamiltonian method [4] to screen the impact of distribution and agglomeration of point defects on the phase diagrams of BaTiO₃-based materials. With this approach, we can simulate up to 10⁶ unit cells and efficiently investigate different defect arrangements. We find that the local fields induced by the defect dipoles play a key role in ferroelectric phase stability and the optimization of functional properties.

[1] Yuri A. Genenko, Julia Glaum, Michael J. Hoffmann, and Karsten Albe. Mater. Sci. Eng. B, 192, 52-82 (2015)

[2] D. Lupascu and J. Rödel. Adv. Eng. Mater. 7(10), 882-898 (2005)

[3] Xiaobing Ren. Nat. Mater. 3(2), 91-94 (2004)

[4] T. Nishimatsu, A. Grünebohm, U. V. Waghmare, M. Kubo, J. Phys. Soc. Jpn. 85, 114714 (2016)