Effects of raw materials on nonhydrolytic sol-gel synthesis of Ba0.6Sr0.4TiO3

The effects of raw materials on the nonhydrolytic sol-gel synthesis of Ba 0.6 Sr 0.4 TiO 3 were systematically studied in this work. The samples were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM). Ba(CH 3 COO) 2 , Sr(CH 3 COO) 2 , BaCO 3 and SrCO 3 can undergo deesterification substitution reaction with Ti(OC 4 H 9 ) 4 to synthesize Ba 0.6 Sr 0.4 TiO 3 phase. Sample taking Ba(CH 3 COO) 2 and Sr(CH 3 COO) 2 as barium and strontium source has better Ba 0.6 Sr 0.4 TiO 3 synthesis results than that of samples using BaCO 3 or SrCO 3 . Ba 0.6 Sr 0.4 TiO 3 phase can not be synthesized at low temperature taking BaCl 2 , SrCl 2 and TiOSO 4 as barium, strontium or titanium source due to their strong ionic bonding. TiCl 4 undergoes an alcoholysis reaction with (oxygen donor) alcohol to form a multimolecular association structure and solvated complex chlorotitanium alkoxide, which reduces the possibility of a deesterification polycondensation reaction. The Ba 0.6 Sr 0.4 TiO 3 phase cannot be synthesized at low temperatures when CH 3 CH 2 OH or C 3 H 7 OH is used as the solvent. The synthesis of Ba 0.6 Sr 0.4 TiO 3 is insufficient because of the coordination ability and solvation effect when CH 3 COOH is used as the solvent. The synthesis of Ba 0.6 Sr 0.4 TiO 3 is the best when Ba(CH 3 COO) 2 , Sr(CH 3 COO) 2 , Ti(OC 4 H 9 ) 4 and glycerol (C 3 H 8 O 3 ) are used as the barium source, strontium source, titanium source and solvent, respectively. Pure Ba 0.6 Sr 0.4 TiO 3 phase with a particle size of 17–43 nm and high dispersion is synthesized when the molar ratio of barium-strontium-titanium is 0.6:0.4:1.2.