Raman scattering of first and second orders by a soft acoustic mode from the Brillouin-zone boundary in Hg2 (ClxBri(1-x)2 crystals
Barta C. , Dobrzhanskii G. F. , Limonov M. F. , Markov Yu. F. , Sigov A. S.
First-order Raman scattering of light by a soft acoustic mode from the boundary of the Brillouin zone has been observed for the first time. This manifestation of the soft mode, which is forbidden in the first-order optical spectra by the selection rules, is induced by long-range static distortions created by substitution defects and composition inhomogeneities of the mixed Hg2 (CI, Br)2 crystals.