For a spherical sodium particle of 25 nm radius crystalizing in a BCC structure having a density of 1.51 g/cm^3, estimate the surface energy of the particle. b. Estimate the surface energy of {100},{110} and {111} surfaces of an FCC lattice with bond strength of 7.97 eV and lattice parameter of 4.2 Å. Also compare the energies.

H1.

Solve 1

1. Write down all the possible Burgers vectors of perfect dislocations in an FCC metal. 2. For an a/2[1 dislocation line moving on a (11-1) plane in an FCC crystal, what are the line directions (in Miller indices) if the dislocation is of (i) pure screw and (ii) pure edge character? For an a/2[1 dislocation line moving on a (11-1) plane in an FCC crystal, what are the line directions (in Miller indices) if the dislocation is of (i) pure screw and (ii) pure edge character?