Inelastic He-atom scattering from the MgO(001) surface

Abstract

Dispersion curves of Rayleigh phonons on an in situ cleaved, room-temperature surface of MgO(001) are determined by time-of-flight measurements of inelastically scattered He atoms. Along both the \ensuremath{\Gamma}\ifmmode\bar\else\textasciimacron\fi{} X\ifmmode\bar\else\textasciimacron\fi{} and \ensuremath{\Gamma}\ifmmode\bar\else\textasciimacron\fi{} M\ifmmode\bar\else\textasciimacron\fi{} directions, the measured phonon frequencies agree fairly well with a shell-model calculation for an unrelaxed MgO(001) surface.