Energy distribution of thermally stimulated exoelectrons from MgO after low-energy electron bombardment

The energy distribution of thermally stimulated exoelectrons around 150degC from MgO(001) surfaces after bombardment at room temperature with electrons at incident energies (Ep) between 75 eV and 3 keV has been measured in ultrahigh vacuum using the retarding potential difference method. The differential distribution usually shows a single peak. Depending on Ep and conditions of ambient gas adsorption, the retarding voltage which presents peak shifts from about 3 to 16 V and the width from about 3 to 10 eV. The charge distribution in surface regions with such width is discussed using the charge density distribution function proposed by Kortov et al. (author)