Roughening of close-packed singular surfaces
  An upper bound to the roughening temperature of a close-packed singular surface, fcc Al (111), is obtained via free energy calculations based on thermodynamic integration using the embedded-atom interaction model. Roughening of Al (111) is predicted to occur at around 890 K, well below bulk melting (933 K), and it should therefore be observable, save for possible kinetic hindering. 
F. Trudu, V. Fiorentini, P. Ruggerone (Cagliari), U. Hansen (Munich)