Regensburg 2010 – wissenschaftliches Programm
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KR: Fachverband Kristallographie
KR 10: Poster: Multiferroics (with MA, DF, KR, DS)
KR 10.17: Poster
Dienstag, 23. März 2010, 10:45–13:45, Poster A
First-principles study of ferroelectric domain walls in multiferroic bismuth ferrite — Axel Lubk1, 2, •Sibylle Gemming3, and Nicola Spaldin2 — 1Institute of Physics, Technical University, D-01062 Germany. — 2Materials Department, University of California, Santa Barbara, California 93106-5050, USA. — 3Inst. Ion Beam Physics and Materials Research, FZ Dresden-Rossendorf, D-01314 Dresden, Germany.
The structural, electronic, and magnetic properties of the ferroelectric domain walls in multiferroic BiFeO3 were studied by density-functional band-structure calculations. Domain walls in which the rotations of the oxygen octahedra do not change their phase when the polarization reorients are the most favorable and of these, the 109∘ domain wall centered around the BiO plane has the lowest energy. The 109∘ and 180∘ walls have a significant change in the component of their polarization perpendicular to the wall; the corresponding step in the electrostatic potential is consistent with a recent report of electrical conductivity at the domain walls. Finally, we show that changes in the Fe-O-Fe bond angles at the domain walls cause changes in the canting of the Fe magnetic moments which can enhance the local magnetization at the domain walls.
Seidel et al., Nature Mater 8 (2009) 229; [2] Lubk et al., Phys. Rev. B 80 (2009) 104110.