Reduction of charge fluctuation energies in ultrathin NiO films on Ag(001)

• Published in: Surface science Vol. 616; pp. 12 - 18
• Main Authors: Yang, Seolun, Park, H.-K., Kim, J.-S., Phark, S.-H., Chang, Young Jun, Noh, T.W., Hwang, H.-N., Hwang, C.-C., Kim, H.-D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.10.2013; Elsevier
• Subjects: Charge; Charge transfer energy; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Coulomb correlation energy; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fluctuation; Image charge potential; Mathematical models; Nickel; Oxide coatings; Physics; Polarization energy; Reduction; Thin films; Ultrathin NiO film; X-rays; Polarization energy; Ultrathin NiO film; Coulomb correlation energy; Charge transfer energy; Ag; Image charge potential; Ultrathin films; Inorganic compounds; Transition element compounds; Coulomb field; Image potential; Charge transfer; Energy transfer; Nickel oxide
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2013.05.012

As the film becomes atomically thin, the on-site Coulomb interaction energy between two 3p holes of the NiO films on Ag(001) U (Ni 3p) significantly decreases as revealed by both X-ray photoelectron and Auger electron spectroscopies. The reduction of U (Ni 3p) for the ultrathin films is well accounted for by varied image potentials and polarization energies in the films from their bulk values. The present results confirm a previous model predicting the reduction of charge fluctuation energies in ultrathin oxide films on highly polarizable substrates due to the extra-atomic relaxations.