Dr. Stephan Krohns
Experimental Physics V, University of Augsburg
Electric-field poling of improper ferroelectrics - step towards domain wall based nano electronics?
Manipulating domains within ferroelectric semiconductors has attracted attention in recent years for potentially allowing domains and domain walls to be used as functional elements in nanoelectronics. One type of multiferroic material, hexagonal manganites, has shown particular potential because of their unusual, improper ferroelectric properties. We report an electric-field poling study of the geometric-driven improper ferroelectric h-ErMnO3. From a detailed dielectric analysis, we deduce the temperature- and frequency-dependent range for which single-crystalline h-ErMnO3 exhibits purely intrinsic dielectric behavior. This provides a comprehensive experimental study addressing the switching dynamics in hexagonal manganites. Controlling the domain walls via electric fields brings us an important step closer to their utilization in resource-efficient domain-wall-based electronics.
 C. Helbig, C. Kolotzek, A. Thorenz, A. Reller, A. Tuma, M. Schafnitzel, S. Krohns, Benefits of Resource Strategy for Sustainable Materials Research and Development, Sustainable Materials and Technologies 12, 1–8 (2017).
 E. Ruff, S. Krohns, M. Lilienblum, D. Meier, M. Fiebig, P. Lunkenheimer, A. Loidl, Conductivity contrast and tunneling charge transport in the vortex-like ferroelectric domain patterns of multiferroic hexagonal YMnO3, Phys. Rev. Lett. 118, 036803 (2017)
 A. Ruff, Z. Li, A. Loidl, J. Schaab, M. Fiebig, A. Cano, Z. Yan, E. Boureet, J. Glaum, D. Meier, S. Krohns, Freqeuncy dependent polarisation switching in h-ErMnO3, Appl. Phys. Lett. 112, 182908 (2018).
 T.S. Holstad, D.M. Evans, A. Ruff, D.R. Smabraten, J. Schaab, Ch. Tzschaschel, Z. Yan, E. Bourret, S.M. Selbach, S. Krohns, D. Meier, Electronic bulk and domain wall properties in B-Site doped hexagonal ErMnO3, Phys. Rev. B 97, 085143 (2018).
 J. Schaab, S.H. Skjaervo, S. Krohns, X. Dai, M. Holtz, A. Cano, M. Lilienblum, Z. Yan, E. Bourret, D.A. Muller, M. Fiebig, S.M. Selbach, D. Meier, Electrical half-wave rectification at improper ferroelectric domain walls, arXiv:1803.08253