XPS STUDY OF MICA SURFACES

Muscovite mica surfaces were studied with X-ray photoelectron spectros copy. The air-cleaved mica surfaces showed a large Cis peak in the ran ge 285.3-285.9 eV indicating the presence of carbon species other than the adventitious. Normal emission and grazing emission spectra were u tilised to calculate bulk and surface elemental ratios respectively fo r air-cleaved as well as vacuum-cleaved mica surfaces. Preferential at tenuation of some peaks has been proposed for a few abnormal elemental ratios. Apparent shifts in binding energy due to sample charging were investigated for differently treated mica surfaces. Changes in the ap parent shift are shown to be due to the existence of strong dipole fie lds at the surface resulting in a potential drop of as much as 3.6V ac ross the dipole layer.