Strains and optical phonons in material systems

Various aspects of strains and optical phonons and their practical uses in material characterization through Raman spectroscopy are discussed. The emphasis is given to elastic and thermal strains and piezoelectric effects, in bulk materials and material systems, such as heterojunctions and superlattices. Tuning of the strain/stress components with an external hydrostatic pressure is also discussed. Specific cases are worked out in detail.