BaTi (BT) double alkoxides were synthesized by refluxing Ba and Ti methoxye
thoxides. The gelation behaviours of the mixed alkoxides and BT double alko
xide, and the evolution of BT double alkoxide structure were investigated.
A remarkable increment in gelation time was found for the synthesized doubl
e alkoxide system, compared with the mixed Ba and Ti alkoxide. In the case
of the double alkoxides it was also observed that the gelation time was gre
atly influenced by the refluxing time used during their synthesis. A shorte
st gelation time was observed in the double alkoxides for refluxing times i
n the range of 2-3 h, attributed to the evolution of their oligomeric struc
ture during the refluxing period. The evolution can be suggested as a trans
ition between non-crystalline and crystalline states, with the shortest gel
ation time being observed near the crystalline state. The application of BT
double alkoxides as precursors enabled a higher degree of homogeneity to b
e achieved during the sol-gel transition, and the obtaining of the BaTiO3 c
rystalline phase at lower temperatures (from 600 degrees C), compared with
the mixed alkoxides (750 degrees C). (C) 2000 Elsevier Science B.V. All rig
hts reserved.