Raman investigation of the phonon spectrum in single crystalline β‐boron

Abstract
The Raman spectra of β‐rhombohedral boron are reported. Approximately 10 broad structures are found, a number which is much less than the 83 phonons allowed in first order Raman scattering. In addition, the symmetry selection rules do not hold for these broad peaks. They are thought to be groups of close lying phonon modes, which might have different symmetry and are broadened by damping. The Raman density of states is discussed.