上游克通大学 SHANGHAI JIAO TONG UNIVERSITY Approximate Calculation of Solid Surface Energy (2) If we cleave a face-centered cubic crystal along a(111)plane,three bonds per atom will be broken.Two surfaces formed,the work required to form the surfaces will be 38/2 per surface atom. Per atom 3 △Hs (for Z=12) △Hs V6/4a W= S= 2 ANA 0.5ZN4 △H V2/2a 4N aov2 N/A is the number of atoms per unit (Face diagonal) area.For fec structure: Figure 4.2 Atomic packing on the (111)face of a face-centered N 4 cubic crystal. A 3a6 A/N= >a0* a=3a2 4 parallelogram 4 11
Approximate Calculation of Solid Surface Energy （2） 11 Per atom parallelogram
上游充通大￥ Face Center Cubic (111) SHANGHAI JIAO TONG UNIVERSITY Face-centered cubic (001) 100) (110) a (0I0) 图6-6面心立方品格的低指数面 D a 2 (100) (111) 12
Face Center Cubic (111) 12 a (111) (100)