Aluminosilicate and alumina gels have been investigated by SANS. Some
curves were compared with SAXS data for estimating the incoherent back
ground due to the H-content of the samples. For alumino-silicate gels
the results indicate a growing substitution of Si by Al ions in the ne
twork with the decreasing water content of the initial solution. On th
e curves of alumina gels shoulders can be observed which may belong to
different characteristic lengths in the gel structure.