Hall mobilities and sheet carrier densities in a single LiNbO${}_3$ conductive ferroelectric domain wall

Abstract

For the last decade, conductive domain walls (CDWs) in single crystals of the uniaxial model ferroelectric lithium niobate (LiNbO${}_3$, LNO) have shown to reach resistances more than 10 orders of magnitude lower as compared to the surrounding bulk, with charge carriers being firmly confined to sheets of a few nanometers in width. LNO thus currently witnesses an increased attention since bearing the potential for variably designing room-temperature nanoelectronic circuits and devices based on such CDWs. In this context, the reliable determination of the fundamental transport parameters of LNO CDWs, in particular the 2D charge carrier density $n_{2D}$ and the Hall mobility ${\mu }_H$ of the majority carriers, are of highest interest. In this contribution, we present and apply a robust and easy-to-prepare Hall-effect measurement setup by adapting the standard 4-probe van-der-Pauw method to contact a single, hexagonally-shaped domain wall that fully penetrates the 200-$\mu$m-thick LNO bulk single crystal. We then determine $n_{2D}$ and ${\mu }_H$ for a set of external magnetic fields $B$ and prove the expected cosine-like angular dependence of the Hall voltage. Lastly, we present photo-Hall measurements of one and the same DW, by determining the impact of super-bandgap illumination on the 2D charge carrier density $n_{2D}$.

References in corpus (3)

• 2D materials and van der Waals heterostructures
• Ultra-High Carrier Mobilities in Ferroelectric Domain Wall Corbino Cones at Room Temperature
• Large Hall electron mobilities in head-to-head BaTiO${}_3$-domain walls

Cited by in corpus (5)

• R2D2 -- An equivalent-circuit model that quantitatively describes domain wall conductivity in ferroelectric LiNbO${}_3$
• Towards the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals
• Probing Ferroelectric Phase Transitions in Barium Titanate Single Crystals via $in-situ$ Second Harmonic Generation Microscopy
• Demonstration of domain wall current in MgO-doped lithium niobate single crystals up to 400 °C
• Current Flow Mapping in Conducting Ferroelectric Domain Walls using Scanning NV-Magnetometry