Regensburg 2022 – wissenschaftliches Programm
KFM 7.5: Vortrag
Montag, 5. September 2022, 16:45–17:05, H5
Oxygen off-stoichiometry and domain wall conductance in ErMnO3 — •Leonie Richarz1, Jan Schultheiß1, Edith Bourret2,3, Zewu Yan3, Antonius T.J. van Helvoort1, and Dennis Meier1 — 1NTNU Norwegian University of Science and Technology, Trondheim, Norway — 2ETH Zurich, Switzerland — 3Lawrence Berkeley National Laboratory, Berkeley, CA, USA
Ferroelectric domain walls are natural interfaces, separating volumes with different orientation of the spontaneous polarization. Due to their symmetry, electrostatics, and strain, the walls can develop completely different electronic properties than the surrounding domains. In ferroelectric oxides, oxygen off-stoichiometry is an additional versatile control parameter. This is reflected by the neutral ferroelectric domain walls in hexagonal manganites: Depending on the oxygen content, their conduction behavior varies from insulating to highly conducting.
In this work, we monitor the electronic transport properties at the domain walls as a function of temperature and oxygen partial pressure with nanoscale spatial resolution. Conductive atomic force microscopy measurements on high-quality ErMnO3 single crystals show anomalous conductance at the domain walls within the whole temperature range of 25 to 300∘C. Furthermore, we find that by annealing the sample in nitrogen, the domain wall conductance can be enhanced. Our results provide new insight into the impact of environmental parameters on the electronic domain wall properties. This is of interest for the development of atmospheric sensors, adding a new direction to the field of domain wall nanotechnology.