Surface Conduction on Poled BaTiO₃ Single Crystals in Ultra High Vacuum

Abstract

We report the experimental verifications that the clean free surface of ferroelectric has an intrinsic electron/hole layer, which exists below the ferroelectric phase-transition temperature, by measuring the surface conduction of BaTiO ₃ single crystals in ultra high vacuum. To our knowledge, the electrically controlled formation of both electron and hole surface conduction layer that are nonvolatile is demonstrated for the first time. The existence of the intrinsic surface electron/hole layer is also a proof that the ferroelectric polarization reaches the top surface, which has important implication in nano-ferroelectrics.

Keywords:

• surface
• surface layer
• conduction
• phase transition
• polarization

Acknowledgment

This work is supported by Grants-in-aid for Scientific Research from JSPS No. 16340093 and No. 17651063.