Surface Debye temperatures of rhodium (100) and (111) surfaces

Abstract

Surface Debye temperatures have been measured for rhodium (100) and (111) surfaces using a conventional low-energy-electron-diffraction-Auger-electron-spectroscopy system. The 00 beam intensities were measured with a spot photometer and the crystal temperature was monitored with a Pt versus Pt-10 at.% Rh thermocouple. From the intensity versus temperature curve, a Debye temperature was calculated for each beam voltage. The surface Debye temperatures were then estimated from plots of Debye temperature versus beam voltage. Using three-constant and five-constant lattice-dynamical models, we have made calculations of the bulk phonon dispersion curves and the surface Debye temperatures. A comparison is given of the experimental and theoretical results for the surface Debye temperatures.