【摘要】 采用溶胶-凝胶和自蔓延燃烧技术,制备了平均晶粒尺寸约20nm的Ba0.5Sr0.5TiO3(BST)纳米粉体。将纳米粉体压制成形后进行烧结,得到BST陶瓷。采用XRD、SEM、TEM和LCR数字电桥研究了BST的结构、形貌和介电性质。结果表明,干凝胶自蔓延燃烧后,可直接形成分散性好、颗粒尺寸均匀、具有钙钛矿结构的BST纳米粉体。BST陶瓷压片经1250℃烧结2h后获得了致密的结构和相对较大的介电常数。粉体的结晶温度和烧结体的烧结温度均低于传统工艺。很明显,溶胶-凝胶自蔓延燃烧法在纳米材料的制备方面具有明显的技术优势。更多还原

【Abstract】 Ba0.5Sr0.5TiO3(BST) nanopowder with crystal size about 20nm was synthesized by a sol-gel and self-propagating combustion process.BST powder was pressed into pellets and then sintered at near 1200℃.The structure,morphology and dielectric properties of BST were studied via XRD,SEM,TEM and LCR analyzer.The as-burnt powder was of perovskite structure,good dispersivity and uniform size.A compact structure with high dielectric constant could be obtained after being annealed at 1250℃ for 2h.The crystallizing point of BST powder and the sintering temperature of BST ceramics were much lower than that of corresponding BST materials prepared by conventional solid state reaction.It disclosed that the sol-gel self-propagating combustion synthesis method had obvious technique advantage in nanometer materials synthesis.更多还原