Hall effect in charged conducting ferroelectric domain walls

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Enhanced conductivity at ferroelectric domain walls is known.
• Fundamental aspects like carrier type, density, and mobility remain largely undetermined.
• Transport mechanisms in these domains are poorly understood.

Purpose of the Study:

• To investigate the fundamental aspects of electrical conduction in ferroelectric domain walls.
• To determine carrier types, densities, and mobilities.
• To elucidate transport mechanisms using advanced microscopy.

Main Methods:

• Utilized intermittent-contact atomic force microscopy (AFM) to detect the Hall effect.
• Studied YbMnO3 single crystals with conducting domain walls.
• Calibrated AFM signals for quantitative analysis.

Main Results:

• Successfully detected the Hall effect in conducting domain walls.
• Confirmed p-type conduction in tail-to-tail charged domain walls of YbMnO3.
• Estimated mobile carrier density in the wall to be ~1 × 10^16 cm^-3.
• Calculated carrier mobility of ~50 cm^2V^-1s^-1.

Conclusions:

• Intermittent-contact AFM is a viable method for studying Hall effect in domain walls.
• The determined carrier density is insufficient for complete screening of polar discontinuity.
• The calculated carrier mobility suggests transport is not dominated by small polaron hopping.