Surface segregation in Nb-doped BaTiO<sub>3</sub> films
Idioma
en
Article de revue
Este ítem está publicado en
Applied Surface Science. 2010, vol. 256, n° 21, p. 6228-6232
Elsevier
Resumen en inglés
We have used in situ photoemission spectroscopy to investigate Niobium doping in polycristalline BaTiO<sub>3</sub>. The valence band maximum position progressively shifts from 2.5 eV for undoped to 2.84 eV for Nb-doped ...Leer más >
We have used in situ photoemission spectroscopy to investigate Niobium doping in polycristalline BaTiO<sub>3</sub>. The valence band maximum position progressively shifts from 2.5 eV for undoped to 2.84 eV for Nb-doped films. Ceramics and single crystal have been investigated for comparison with thin films. Nb-doped BaTiO<sub>3</sub> ceramics and Nb-doped SrTiO<sub>3</sub> single crystal show higher Fermi level position indicating that our doped films are less conducting regarding their bulk parents. This was confirmed by impedance spectroscopy under variable temperature. Large amount of niobium is clearly observable at surface but the amount of dopant is drastically reduced below the near-surface region, as evidenced by depth profile. Therefore, we provide evidence of surface segregation which would explain the contrasted resistivity values reported in literature for such donor-doped films.< Leer menos
Palabras clave en inglés
BaTiO3
Titanates
Films
PTCR
Segregation
Surfaces
XPS
Orígen
Importado de HalCentros de investigación