Direct Scattering Studies of the Melting of Lead Surfaces.

We report diffuse scattering studies of liquid layers on the Pb (110) and (111) surfaces at temperatures substantially below the melting point of Pb. Surprisingly, the initial liquid scattering appears at ~~230K or 1/2T sub m on both the (110) and the (111) surfaces. On the (110) surface, analysis of the scattered intensity yields 2-3 monolayers of liquid from 575K to 599K while substantially less than 1 monolayer of liquid is present on the (111) surface.