Abstract
We report experimental observation of electron (e −)/hole (h +) layer on the clean surface of insulating pure BaTiO3 single crystals in ultra high vacuum (UHV < 10−8 Pa). To our knowledge this is the first report of the bipolar surface carrier layer by the field effect on any oxide. The experiments here verify that both accumulation and inversion occur and the surface carrier layer is intrinsic, i.e., due to spontaneous polarization P S not to impurities and defects.
Acknowledgments
This work is supported by Grants-in-aid for Scientific Research from JSPS No. 19340084.