Anorthite and CaAl2Si2O8 glass: low frequency Raman spectroscopy and neutron scattering

Abstract Raman spectra of anorthite crystal and glass have been obtained on a wide frequency range from 5 to 1200 cm −1 . Medium-range order has been pointed out in this study: numerous low frequency peaks in anorthite have been observed and a comparison with the well known band around 60 cm −1 in the Raman spectrum of anorthite glass is made. In order to probe the medium-range structure of CaAl 2 Si 2 O 8 glass, a comparison between neutron inelastic scattering, Raman low frequency vibrations and heat capacity data is done for both glass and crystal.