Abstract: Nanosize polycrystalline powders of lanthanum doped barium titanate were prepared by the cosolubilized-
hydrous gel process using titanium butoxide and lanthanum acetate as well as barium acetate with 0.7mol/L total concentration of precursor. The sol was
obtained by cosolubilized hydrosis of starting materials using HOAc as medium and catalyst with pH=3.8. The wet-gel was acquired by concentrating and aging
sol at room temperature. The wet-gel to dry-gel conversion was performed at 50℃/24h in an electrical oven. The TG-DTG measurement of dry-gel
was carried out to determine the appropriate temperature range of calcination. Then a series of polycrystal powders were prepared by calcining dry-gel at different points of above temperature range. Powder samples were characterized detailedly to confirm
the phase formation, crystalline size, grain morphology, elemental composition and the fine structure by FT-IR, XRD, SEM, EDS, TEM and LRS. So that opitimizing
800℃/2h as the suitable condition for calcination of dry-gel to prepare nanosize polycrystal powders La_xBa_1-xTiO ₃(x=0.00, 005,
0.10, 0.20, 0.30).

Key words: modification of La³⁺-doped barium titanate （La_xBa_1-x cosolubilized hydrous-gel process, nanosize polycrystal powders, microstructure characterizations