SOL-GEL PREPARATION AND OPTICAL NONLINEARITY OF LEAD(II) OXIDE TITANIUM(IV) OXIDE AMORPHOUS MONOLITHS

PbO-TiO2 amorphous monoliths with TiO2 content from 60 to 80 mol% were prepared by the sol-gel method using Pb-Ti complex alkoxides synthesized from Pb(CH3COO)2. 3H2O and Ti(O.C3H7i)4. The thermal evolution process of the gel was examined by means of DTA/TG, IR spectroscopy, and X-ray diffraction techniques. Dehydrated, transparent, amorphous monoliths were obtained in the temperature range from 350-degrees- to 550-degrees-C, depending on the composition. The refractive index of those amorphous monoliths was higher than 2.0, and the third-order optical nonlinear susceptibility, chi(3), evaluated from third harmonic generation (THG) was on the order of 10(-12) esu.