Regensburg 2016 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 8: Focus Session: Ferroic Domain Walls II

DF 8.3: Vortrag

Dienstag, 8. März 2016, 14:45–15:00, H25

Controlling electronic domain-wall conductance by charge-carrier doping — •Jakob Schaab¹, Andres Cano², Hatice Doganay³, Daniel Gottlob³, Ingo P Krug⁴, Claus M Schneider³, Ramamoorthy Ramesh⁵, Manfred Fiebig¹, and Dennis Meier¹ — ¹ETH Zürich — ²CNRS, Univ. Bordeaux — ³FZ Jülich — ⁴TU Berlin — ⁵UC Berkeley

The electronic transport at ferroelectric domain walls bears great application potential in the field of nano-electronics. The precise control and optimization of domain-wall properties towards technologically useful regimes, however, remains a major challenge. A promising but largely unexplored route is to implant specific acceptor or donor atoms, as known from conventional semiconductor physics, and thereby tailor the performance of the domain-wall transport. Here, we discuss to the perspectives of charge-carrier doping for tuning the electronic transport properties at ferroelectric domain walls. In Er_1−xCa_xMnO₃ we modify the domain-wall conductance by replacing trivalent Er³⁺ for divalent Ca²⁺. A doping level of 1% is found to enhance the local conductance by a factor of ≈ 50. In addition, leakage effects at the domain walls are suppressed, reducing their effective width by about 50%. The higher conductance, together with the reduced domain-wall width, leads to a significant enhancement of the current density carried by the walls, which we characterize using scanning probe and photoemission electron microscopy. Our study demonstrates chemical charge-carrier doping as powerful and easily controllable approach for engineering and improving the functionality of ferroelectric domain walls.