14  Experimental Methods for Thermal Properties (optional)

NoteLearning Objectives

• Explain how phonon information is extracted from absorption and inelastic scattering experiments.
• Distinguish what infrared absorption, Raman scattering, Brillouin scattering, and neutron scattering can measure.
• Use energy and crystal-momentum conservation to understand which phonons are experimentally accessible.
• Derive the Brillouin frequency shift and interpret Stokes and anti-Stokes processes.
• Read the one-phonon neutron-scattering cross section and identify what sets peak position, intensity, and width.