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Hysteresis in the I – V Tunneling Characteristics of n ‐Type BaTiO 3 Ceramics
Author(s) -
Kolodiazhnyi Taras V.,
Thomas Daniel F.
Publication year - 2000
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2000.tb01160.x
Subject(s) - fermi level , hysteresis , materials science , band gap , condensed matter physics , scanning tunneling microscope , scanning tunneling spectroscopy , schottky barrier , oxygen , desorption , quantum tunnelling , analytical chemistry (journal) , chemistry , adsorption , diode , nanotechnology , optoelectronics , physics , electron , organic chemistry , quantum mechanics , chromatography
Scanning tunneling microscopy (STM) and spectroscopy (STS) have been applied to study the surface electronic properties of n ‐type BaTiO 3 ceramics under ultrahigh vacuum and at various oxygen partial pressures. I – V tunneling characteristics of vacuum‐annealed BaTiO 3 do not exhibit rectifying behavior, implying that the Fermi level is pinned at the surface. The surface band gap of BaTiO 3 annealed under vacuum at 540°C is equal to 1 eV. The top edge of the surface valence band is located 0.7 eV below the Fermi level. Hysteresis in the I – V characteristics has been observed at high oxygen partial pressures. Dosing of the BaTiO 3 with oxygen increases the surface band gap and unpins the Fermi level. As a result, the I – V characteristics acquire rectifying features similar to those observed for BaTiO 3 Schottky‐type diodes. Hysteresis in the I – V spectra observed at high oxygen partial pressures is attributed to the changes of the surface potential barrier due to adsorption/desorption of oxygen modulated by the tip‐sample potential difference.