沉淀混合法合成Ba_2Ti_9O_(20)粉体

SYNTHESIS OF Ba_2Ti_9O_(20) POWDER BY PRECIPITATION-MIXING METHOD

对沉淀混合法合成单相Ba2 Ti9O2 0 粉体做了初步的探索 ,并在较短时间内煅烧得到单相Ba2 Ti9O2 0 。采用BaCO3和钛酸丁酯为原料 ,在pH≈ 9的条件下获得草酸钡和氢氧化钛沉淀 ,然后将二者混合 ,洗涤、过滤、烘干后 ,经不同温度煅烧 ,得到最后的粉体。在前驱体的制备过程中 ,不需要高、低温或保护性气体等特殊要求。研究结果显示 :经 12 0 0℃下煅烧 2h ,可得到单相的Ba2 Ti9O2 0 粉体。进一步的研究表明 :以球磨混合的方式在前驱体中添加适量的Ba2 Ti9O2 0 晶种能有效降低Ba2 Ti9O2 0 相的形成温度 ,在 115 0℃下煅烧 2～ 4h可得到单相的Ba2Ti9O2 0

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.