Electronic bulk and domain wall properties in B-site doped hexagonal ErMnO$_3

• Main Authors: Holstad, T. S, Evans, D. M, Ruff, A, Smaabraaten, D. R, Schaab, J, Tzschaschel, Ch, Yan, Z, Bourret, E, Selbach, S. M, Krohns, S, Meier, D
• Format: Journal Article
• Language: English
• Published: 16.10.2017
• Subjects: Physics - Materials Science
• DOI: 10.48550/arxiv.1710.05557

Phys. Rev. B 97, 085143 (2018) Acceptor and donor doping is a standard for tailoring semiconductors. More recently, doping was adapted to optimize the behavior at ferroelectric domain walls. In contrast to more than a century of research on semiconductors, the impact of chemical substitutions on the local electronic response at domain walls is largely unexplored. Here, the hexagonal manganite ErMnO$_3$ is donor doped with Ti$^{4+}$. Density functional theory calculations show that Ti$^{4+}$ goes to the B-site, replacing Mn$^{3+}$. Scanning probe microscopy measurements confirm the robustness of the ferroelectric domain template. The electronic transport at both macro- and nanoscopic length scales is characterized. The measurements demonstrate the intrinsic nature of emergent domain wall currents and point towards Poole-Frenkel conductance as the dominant transport mechanism. Aside from the new insight into the electronic properties of hexagonal manganites, B-site doping adds an additional degree of freedom for tuning the domain wall functionality.