Porous anodic alumina (PAA) films with pore and cell sizes ranging from 170 to 190 and 240
to 270 nm, respectively, have been generated on aluminum and monocrystalline silicon substrates
followed by spin-on sol-gel derived coating with the subsequent thermal treatment producing
microporous xerogel. The distribution of the xerogels corresponding to the chemical contents of
willemite, garnet, titania, alumina, doped with terbium and strontium in PAA was investigated. Most
xerogels, after annealing at 1000 °C, are mainly distributed near the pore bases, leaving much of the
pore volume unfilled