Vol. 42, Issue 2, pp. 271-280 (2012)

Abstract

Microscopic structure of three types of porous glasses with the average pore diameter of 5, 7 and 140 nm obtained by chemical etching was studied by neutron diffraction. The analysis of diffraction patterns has shown that in these glasses, besides an amorphous phase forming a weakly structured background, there are microscopic crystalline inclusions of sassolite with a diffraction size of 26±3 nm and of α-quartz with a characteristic size of 6±1 nm. Microcrystalline inclusions sizes do not depend on the average pore size diameter. It is shown that in these samples a tridymite phase does not make a significant contribution to observed scattering and a relative sassolite contribution decreases substantially with the average pore size increasing from 5 to 140 nm.