Synthesis of Ba2Ti9O20 powder by precipitation-mixing method

Primary investigation on the synthesis of Ba2Ti9O20 powders by the precipitation-mixing method was reported. By using this method pure phase Ba2Ti9O20 powder was obtained easily at a short dwelling time. Taking Ti(OC4H9)4 and BaCO3 as raw materials, BaC2O4 precipitate and Ti(OH)4 precipitate were first formed separately under the condition of pH=9, then by pulling BaC2O4 precipitate into Ti(OH)4 precipitate to form a homogeneous mixture. The mixed precipitates were washed, dried and calcined at different temperatures to obtain the final powder. During the precursor preparing process, no special conditions such as high/low temperature or protective atmosphere were needed. Single phase Ba2Ti9O20 powder could be synthesized after calcining at 1200°C for only 2 h. The investigation also shows that adding seeds in the precursor by the mechanical milling method is an effective way to lower the forming temperature for single-phase Ba2Ti9O20. With seeds added, single-phase Ba2Ti9O20 can be obtained at 1150°C for 2-4 h.