Fundamental aspects of conduction in charged ErMnO 3 domain walls

James McCartan, Patrick W. Turner, James P. V. McConville, Kristina Holsgrove, Charlotte Cochard, Amit Kumar, Raymond G. P. McQuaid, Dennis Meier, J. Marty Gregg*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

42 Downloads (Pure)

Abstract

It is now well‐established that ferroelectric domain walls, at which there are discontinuities in polarization, are usually electrically conducting. Yet, there is a dearth of rather basic information on the physics underpinning conductivity. Here, Kelvin Probe Force Microscopy (KPFM)‐based experiments are reported, which allow significant new insights regarding charge transport at domain walls in ErMnO3. In one set of experiments, KPFM is used to spatially map the Hall potential, developed at the surface of polished single crystals. These maps provide direct experimental evidence that n‐type head‐to‐head domain walls arise in otherwise p‐type material. In another set of experiments, the geometry for current flow is restricted, by cutting sub‐micron thick lamellar slices of ErMnO3 (using a Focused Ion Beam microscope). Separate contacts are made to n and p‐type walls and the potential profiles, when driving source‐drain currents, are measured (again using KPFM). Current‐electric field functions showed Ohmic behaviour for p‐type walls, with an intrinsic room temperature conductivity value of ≈0.4Sm−1. The n‐type walls showed non‐Ohmic behaviour and a significantly lower conductivity, supporting the prediction that electrons are in a polaronic state; an upper bound for the room temperature conductivity of the domains themselves is ≈6 × 10−6Sm−1 at 0.1 MVm−1.
Original languageEnglish
Article number2400091
Number of pages8
JournalAdvanced Electronic Materials
Early online date22 Apr 2024
DOIs
Publication statusEarly online date - 22 Apr 2024

Keywords

  • conductivity
  • ferroelectric domain wall
  • charge transport
  • Kelvin Probe Force Microscopy

Fingerprint

Dive into the research topics of 'Fundamental aspects of conduction in charged ErMnO 3 domain walls'. Together they form a unique fingerprint.

Cite this