a) Draw schematically the arrangement of atoms in the {111}, {100} and {110} surface planes of a crystal with fcc lattice and determine the number of nearest neighbours of the surface atoms for each of the three surfaces.
b) What is the smallest interatomic distance within (i) a fcc lattice and (ii) a bcc lattice when the bulk lattice parameter is ab? Note: the bulk lattice parameter ab is the length of the edge of the cubic unit cell.
c) Calculate the surface atom density (in atoms per m2) for the {111}, {100}, and {110} surfaces of Cu (fcc bulk lattice with lattice parameter ab = 0.361 nm).
d) Calculate the surface energies for the three Ni surfaces (ΔHsub = 336 kJ mol-1) above and verify the ratio 1 : 1.15 : 1.22 between {111}, {100} and {110}.