A study was made of the surface dynamics, near to the reconstruction transition of (100), by using a model Hamiltonian and Brownian molecular dynamics simulation. It was possible to avoid the marked size limitations of previous molecular dynamics studies by using an effectively 2-dimensional Hamiltonian and by analysing the results by using dynamic scaling theory. The static and dynamic critical exponents for this transition, which belonged to the universality class of the XY model with 4-fold anisotropy, were determined. The central peak of the phonon spectrum was related to the friction which was experienced by an adatom on this surface. The adatom diffusion constant on this surface was predicted to vanish, at the transition point, due to the divergent frictional damping. The divergent nature of the friction near to the transition was not specific to this system, and was expected to occur near to other continuous phase transitions such as surface pre-roughening and vortex-lattice melting.

Dynamics Near the Surface Reconstruction of W(100). M.R.Baldan, E.Granato, S.C.Ying: Physical Review B, 2000, 62[3], 2146-50