ENERGY-DEPENDENCE OF THE ELECTRON ATTENUATION LENGTH IN LEAD ARACHIDATE LANGMUIR-BLODGETT-FILMS

The attenuation lengths for electrons in the kinetic-energy range 1350-550 eV in lead arachidate (C19H39COO)2Pb] Langmuir-Blodgett films have been determined from measurements of the x-ray photoemission intensity variation with electron takeoff angle. Attenuation lengths are determined from an elementary layer model proposed in the paper. The layer model increases the kinetic-energy range over which attenuation lengths can be determined and is thus more versatile than the overlayer method. The Bethe equation for inelastic scattering of electrons is found to describe the energy dependence of the measured attenuation lengths quite well. The material dependence of the Bethe parameters determined by Tanuma, Powell, and Penn [Surf. Interface Anal. 11, 577 (1988)] for some metals, oxides, and insulators does not exist in the case of lead arachidate Langmuir-Blodgett films.