LOW FREQUENCY RAMAN STUDY OF THE HARMONIC VIBRATIONAL MODES IN SILICA AEROGELS J. L. SAUVAJOL, J. PELOUS, T. WOIGNIER et R. VACHERJ. Phys. Colloques, 50 C4 (1989) C4-167-C4-169DOI: https://doi.org/10.1051/jphyscol:1989427