EFFECT OF STATIC UNIAXIAL-STRESS ON THE RAMAN-SPECTRUM OF SILICON (REPRINTED FROM SOLID-STATE COMMUN, VOL 8, PG 133-138, 1970)

We have performed the first experimental investigation of the effects of static uniaxial stress on the frequency of the q almost-equal-to 0 optical phonons in a diamond-type crystal. Application of uniaxial str ess along [001] or [111] is found to cause splittings and shifts of th e Raman peaks of the q almost-equal-to 0 triply degenerate optical pho nons. From the observed splittings we have obtained experimental value s for the phenomenological coefficients which describe the changes in the 'spring constant' of these phonons with strain. Our results are in reasonable agreement with lattice dynamical theory.