The effective-surface Debye temperature for the (100) face of single-crystal vanadium has been measured as a function of incident electron energy in the energy range 0—400 eV using low-energy-electron diffraction. The ratio of surface-to-bulk atomic mean-square displacements has been estimated from the experimental data and has been investigated theoretically. A lattice-dynamical model consisting of central-potential interactions up to fourth neighbors together with harmonic angle-bending interactions is employed. The calculations have been performed using a set of special wave-vector points in the two-dimensional Brillouin zone which are the most efficient in finding the average of a periodic function over the Brillouin zone. Results have been obtained for both unchanged and changed force constants for the surface atoms. A comparison will be given between the experimental and theoretical results.

• Received 25 August 1975

DOI:https://doi.org/10.1103/PhysRevB.12.5599