513.001 Molecular and Solid State Physics

Return to
problem list

Wolfram Alpha

Physical
Constants

Periodic System
of Elements

      

Phonon dispersion, Exam Question 4 - March 11, 2008

An fcc crystal has two atoms per unit cell. Sketch the phonon dispersion relation (frequency vs. wavenumber). On the wavenumber axis, indicate the positions of Γ, X, and L. The first Brillouin zone for an fcc crystal is shown in the following figure.

Phonon dispersion, Exam Question June 29, 2011

A bcc crystal has three atoms per unit cell. Sketch (approximately) the phonon dispersion relation (frequency vs. wavenumber) in the high symmetry directions. The first Brillouin zone for a bcc crystal is shown in the following figure.