Effect of surface oxygen vacancies on electronic states of reduced SrTiO3(110) surface

✍ Scribed by Y. Aiura; H. Bando; T. Maruyama; Y. Nishihara; Y. Haruyama; S. Kodaira; T. Komeda; Y. Sakisaka; H. Kato

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 316 KB
• Volume: 235-240
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)91729-9

✦ Synopsis

The electronic structure of reduced SrTiO3(ll0) surface prepared by annealing in ultrahigh vacuum (UHV), has been studied using photoemission spectroscopy (PES) and scanning tunneling microscopy/spectroscopy (STM/STS). In the PES spectra of reduced SrTiO3(ll0) surface after annealing in UHV at 8(AJ~C, a clear metallic state with a sharp Fermi cut-off and a broad state centered at .-.1.1eV below the Fermi level are observed in the band gap region. A Ti3p->3d resonance enhancement is occurred for the metallic state, but not for the ~l.leV state. On the other hand, after the sample was anneNed in UHV at 1000*C, it has been shown that the metallic state becomes drastically weak, and that only the ~l.leV state is seen in the band gap region. Thereafter, the ~l.leV state exhibits a clear Ti3p->3d resonance enhancement. Tlle difference in the spectral feature of these band gap states is directly related to the surface geometric structural change.