Answer to Question #244959 in Physics for KUMARESAN K

Question

1) The number of phonon branch in graphite, with four atoms in the primitive cell, is:

A) 8, out of which 2 are acoustic and 6 optical
B) 9, out of which 3 are acoustic and 6 optical
C) 12, out of which 3 are acoustic and 9 optical
D) 12, out of which 2 are acoustic and 10 optical

Answer 1

The number of phonon branch in graphite, with four atoms in the primitive cell, is 12, out of which 3 are acoustic and 9 optical.

Answer: C) 12, out of which 3 are acoustic and 9 optical