Surface melting of Pb(110) studied by x-ray photoelectron diffraction

The temperature-dependent forward-scattering intensity of 4${\mathit{f}}_{7/2}$ core-level photoelectrons at 1344.7 eV kinetic energy was studied for a Pb(110) crystal along the [001] and [11¯0] azimuths. The forward-scattering enhancement peaks, as a measure of crystalline order near the surface, decrease slowly up to about 500 K. Above this temperature a much more pronounced decrease is observed, indicative of a disordering of the Pb(110) surface. A change in the growth law of the disordered layer is seen near 575 K.