The limit for zero angle of the intensity of the X-ray scattering by homogeneous substances (liquids or gases) depends on the mean fluctuation of density, wich can be calculated from the isothermal compressibility. This theoretical relation has been verified with some usual liquids. But it is not true for glycerol, probably because the temperature of measurements is very near melting point. We have also found that the density fluctuations in vitreous silica are about half of those of quartz rendered amorphous by neutron irradiation.
No takes yet. Share an insight, caveat, or question.
Levelut et al. (1967) studied this question.