PHYSICS · Multi-part · Fermi University Physics · Condensed Matter, Materials & Soft Matter · Lattice dynamics and thermal properties of solids · Lattice dynamics and thermal properties of solids
Condensed Matter Physics, Ch Two atoms in the cell: acoustic and optical branches
Problem
Find the total number of branches, and the number of each kind, for these three crystals, using the number of atoms in the primitive cell, p, given for each:
((a)) diamond (p=2);
((b)) calcium fluoride, CaF2, whose primitive cell holds one calcium ion and two fluoride ions (p=3);
((c)) barium titanate, BaTiO3, whose primitive cell holds one formula unit, five atoms in all (p=5).