(中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 以KCl為助熔劑，采用熔鹽合成技術(shù)制備片狀(Sr, Ba)TiO3晶粒，研究不同前驅(qū)體及反應(yīng)方式對產(chǎn)物相組成和形貌的影響。結(jié)果表明：BaO與片狀SrTiO3反應(yīng)可獲得以(Sr, Ba)TiO3為主相的產(chǎn)物，產(chǎn)物相在SrTiO3表面無規(guī)則析出且非取向長大，經(jīng)燒結(jié)后形成片狀多晶團(tuán)聚體；片狀Sr3Ti2O7與BaO和TiO2反應(yīng)所得產(chǎn)物也以(Sr, Ba)TiO3為主，同時生成少量(Sr, Ba)3Ti2O7相，產(chǎn)物中除片狀(Sr, Ba)TiO3晶粒外，還通過Sr2+置換由BaO與TiO2反應(yīng)所得塊狀BaTiO3晶粒中的Ba2+、以及反應(yīng)物溶解−反應(yīng)−析出生成許多塊狀和無規(guī)則狀小晶粒；對于兩步合成工藝，Sr3Ti2O7先與BaO反應(yīng)可得到片狀(Sr, Ba)3Ti2O7，與TiO2二次反應(yīng)后得到片狀(Sr, Ba)TiO3晶粒；由于此方式?jīng)]有生成塊狀BaTiO3這一過程，產(chǎn)物中非片狀晶粒數(shù)量大幅度減少。
關(guān)鍵字: (Sr, Ba)TiO3；片狀晶粒；熔鹽合成
（State Key laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The tabular (Sr, Ba)TiO3 particles were prepared in KCl flux by molten salt synthesis. The effects of precursors and reactive modes on the phase composition and morphology of products were investigated. The results show that the product with main phase (Sr, Ba)TiO3 is obtained by reacting SrTiO3 with BaO. The tabular aggregates are formed by sintering irregular grains that precipitate grow arbitrarily on the SrTiO3 surfaces. (Sr, Ba)TiO3 is also the main phase by reacting tabular Sr3Ti2O7 with BaO and TiO2. Besides the tabular (Sr, Ba)TiO3 particles, many small non-tabular particles are generated from the substituting of Sr2+ for Ba2+ in BaTiO3 formed by reacting BaO with TiO2, or the dissolving-reacting-precipitating process. For two-step process, tabular (Sr, Ba)3Ti2O7 particles are obtained by reacting Sr3Ti2O7 with BaO, which further react with TiO2 to form tabular (Sr, Ba)TiO3 particles. Because no BaTiO3 generates, the amount of small non-tabular particles decreases greatly.
Key words: (Sr, Ba)TiO3; tabular template; molten salt synthesis
