surface melting (faceting?) sergio calatroni. surface melting sergio calatroni2 (110) -> 1270 k...
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Surface Melting(faceting?)
Sergio Calatroni
Surface Melting
Sergio Calatroni 2
(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
Stress effect
Sergio Calatroni 3
Cluster size effect
Sergio Calatroni 4
MD from Kai Nordlund
Sergio Calatroni 5
2 ns
~10 nm
Faceting
Sergio Calatroni 6
Faceting happens:• Vacuum 1040 C
• Does not happen:• 1 bar H2 SLAC 1040 C• 1 mbar H2 CERN 1040 C• 10 mbar H2 CERN 850 C
What orientations?
Hydrogen + Cu
Sergio Calatroni 7
1083 C
P = 500 bar!
Missing info: effect of H2 on surface melting
+H
+H
(Cu)+H / L+H
1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+040.0000001
0.000001
0.00001
0.0001
0.001
0.01
0.1
1
Concentration 700 K [H in %]
Concentration 1000 K [H in %]
Concentration 1300 K [H in %]
Concentration 1356 K [H in %]
Concentration 1356 K [H in %]
Concentration 1600 K [H in %]
Pressure [mbar]
Conc
entr
ation
ato
mic
%Hydrogen solubility in Cu
Sergio Calatroni 8
CERN SLAC
liquid
solid
700 K
1000K
1356K
1356K
1600K
0.2%
90 bar
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