Accession Number : ADA150001


Title :   The Valence- and Conduction-Band Structure of the Sapphire (1102) Surface.


Descriptive Note : Technical rept.,


Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY AND BIOCHEMISTRY


Personal Author(s) : Gignac,W J ; Williams,R S ; Kowalczyk,S P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a150001.pdf


Report Date : Dec 1984


Pagination or Media Count : 50


Abstract : X-ray photoelectron and electron energy loss spectroscopies have been employed to investigate the valence- and conduction-band densities-of-states of the sapphire (1102) surface. The photoemission spectrum of the valence-band region has been adjusted to remove cross-section effects and compared to the recent theoretical density-of-states calculated by Ciraci and Batra. The energy loss data have been used to determine the bulk plasmon energy of sapphire, 24.0 +or- .3 eV, as well as the locations of eight regions of high conduction-band state density within 20 eV above the conduction-band minimum. One of these regions is an empty surface state 4.0 eV below the conduction-band minimum. Several high binding energy satellites in the XPS core level spectra are reported and interpreted in terms of energy losses to plasmons and interband transitions. Originator furnished keywords include: Sapphire - Aluminum Oxide - X-ray phtoemission - electron energy loss - plasmon - surface state- density-of-states.


Descriptors :   *CRYSTAL STRUCTURE , *SAPPHIRE , *VALENCE BANDS , *ALUMINUM OXIDES , *CONDUCTION BANDS , ELECTRON ENERGY , SPECTRA , X RAY PHOTOELECTRON SPECTROSCOPY , CROSS SECTIONS , LOSSES , ELECTRON SPECTROSCOPY , PLASMONS


Subject Categories : Crystallography
      Atomic and Molecular Physics and Spectroscopy
      Nuclear Physics & Elementary Particle Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE