Revisiting the hexagonal manganites

Datum

13.04.2012

Zeit

10:00 - 11:00

Sprecher

Prof. Dr. Nicola Spaldin

Zugehörigkeit

Materials Theory, ETH Zurich

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien, Physik

Host

Grit Rötzer

Beschreibung

The hexagonal manganite multiferroics, of which YMnO3 is the prototype, have recently been shown to exhibit a fascinating ferroelectric domain structure [1] which is a consequence of their improper geometric ferroelectricity [2,3]. Here we discuss how this results in topologically protected ferroelectric vortices providing a model system to test theories of cosmic string formation in the early universe. We show how first-principles electronic structure calculations are contributing to the design of test experiments, as well as understanding the coupling between ferroelectricity and magnetism, and the behavior of the ferroelectric domain walls. [1] Fennie, C. J. & Rabe, K. M., Ferroelectric transition in YMnO3 from first principles. Phys. Rev. B 72, 100103 (2005). [2] Van Aken, B. B., Palstra, T. T. M., Filippetti, A. & Spaldin, N. A., The origin of ferroelectricity in magnetoelectric YMnO3. Nature Mater. 3, 164-170 (2004). [3] Choi, T. et al. Insulating interlocked ferroelectric and structural antiphase domain walls in multiferroic YMnO3. Nature Mater. 9, 253-258 (2010) .

Letztmalig verändert: 13.04.2012, 09:35:17