Regularities in the formation of barium oxide films on tungsten tips by field methods

The effects of increasing quantities of barium oxide deposited on the surface of a tungsten tip are monitored by analyzing field-emission images, I-V characteristics and electron energy spectra. Changes are observed in the emission activity of the system throughout the entire adsorption time, as well as the appearance of nonlinear I-V characteristics and a shift in the position of the spectra relative to the Fermi level of the tungsten substrate after the amount of adsorbed barium oxide on the W surface reaches a level that depends on the substrate face. The experimental data set forms the basis of a model for the creation of multilayer films of BaO on W. Fiz. Tverd. Tela (St. Petersburg) 39, 1476–1478 (August 1996)