Approximate Calculation of Solid Surface S.J.T.U. Energy (4) Phase Transformation and Applications Page 14/42 For a(100)plane there are four broken bonds per atom,and the number of atoms per unit area: 2 /(100) a The ratio of the two surface energies: 2 Yam= =1.15 ao Ya00) 3 Figure 4.3 Atomic packing on the (100)face of a face-centered cubic crystal. SJTU Thermodynamics of Materials Spring2008©X.J.Jin Lecture 20 surfacePhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2008 © X. J. Jin Lecture 20 surface Page 14/42 Approximate Calculation of Solid Surface Energy (4) For a (100) plane there are four broken bonds per atom, and the number of atoms per unit area: 2 )100( 0 2 aA N ⎟ = ⎠⎞ ⎜⎝⎛ 15.1 3 2 )100( )111( == γ γ The ratio of the two surface energies: