Regensburg 2016 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 8: Focus Session: Ferroic Domain Walls II

DF 8.2: Vortrag

Dienstag, 8. März 2016, 14:30–14:45, H25

Low-temperature study of semiconducting domain walls in hexagonal manganites — •Peggy Schönherr¹, Jakob Schaab¹, Andres Cano², Manfred Fiebig¹, and Dennis Meier¹ — ¹ETH Zürich, Switzerland — ²CNRS, University Bordeaux, France

Unusual electronic properties arise at domain walls in semiconducting ferroelectrics due to the local electrostatics, their low symmetry and strain. The hexagonal manganites are a particularly interesting example as their improper ferroelectricity naturally leads to simultaneous formation of neutral side-by-side and charged head-to-head and tail-to-tail domain walls. These domain-wall states allow for accessing a wide variety of phenomena, so that the hexagonal manganites represent an ideal playground for studying domain-wall nanoscale physics.

Here, we will discuss temperature-dependent variations in the electronic domain-wall transport in the semiconductor Er_1−xCa_xMnO3. Using low-temperature atomic force microscopy we monitor the ferroelectric domain pattern and investigate changes in the electronic properties of the domain walls for temperatures between 295 K and 4.2 K. Our data demonstrate that the domain walls adopt the basic p-type semiconducting properties of the host materials. Additional modulations in the Schottky barrier, electronic conductance and screening arise according to the local domain-wall charge state. Our result clarify pending questions about the low-temperature performance and stability of charged domain walls and provide new insight to the general domain-wall physics in semiconducting ferroelectrics.