Evidence for a temperature-induced order-disorder phase transition on W(100)

Abstract
High-energy ion scattering measurements on a flat W(100) surface have been carried out in the temperature range 80-600 K. The results indicate conclusively that the surface atoms are displaced laterally at all temperatures. The lateral displacement is estimated as ≈0.14 Å. The low-temperature (2×2)R45° to high-temperature (1×1) phase transition is therefore an order-disorder transition.