1. Surface Melting (faceting?) Sergio Calatroni

2. Surface Melting Sergio Calatroni2 (110) -> 1270 K (1000 C) (100) -> 1290 K (1020 C) (111) -> 1310 K (1040 C) Bulk fusion -> Lindemann criterion: rms thermal vibration amplitude of the solid reaches some 14% of the nearest-neighbour distance. In a surface atoms are closer together than in bulk -> lower melting point

3. Stress effect Sergio Calatroni3

4. Cluster size effect Sergio Calatroni4

5. MD from Kai Nordlund Sergio Calatroni5 2 ns ~10 nm

6. Faceting Sergio Calatroni6 Faceting happens: Vacuum 1040 C Does not happen: 1 bar H 2 SLAC 1040 C 1 mbar H 2 CERN 1040 C 10 mbar H 2 CERN 850 C What orientations?

7. Hydrogen + Cu Sergio Calatroni7 1083 C P = 500 bar! Missing info: effect of H 2 on surface melting +H (Cu)+H / L+H

8. Hydrogen solubility in Cu Sergio Calatroni8 CERN SLAC liquid solid 700 K 1000K 1356K 1600K 0.2% 90 bar