摘要
水热法制备的陶瓷粉体结晶度高，团聚少，烧结活性高，得到了越来越广泛的重视．本文报道了水热法制备ＢａＴｉＯ３粉体的研究结果，给出了ＢａＴｉＯ３粉体晶粒相组成、粒度和结晶形貌与反应温度、前驱物形式以及Ｂａ、Ｔｉ摩尔比之间的关系．选择较高的反应温度，使用强碱性溶液以及较高ｍ（Ｂａ）／ｍ（Ｔｉ）比的前驱物，有利于钙钛矿型ＢａＴｉＯ３晶粒的形成．采用新制的Ｔｉ（ＯＨ）４胶体为前驱物，在Ｂａ（ＯＨ）２水溶液中经水热反应可得晶粒规整、分散性好，粒度在１０ｎｍ以下的钙钛矿型ＢａＴｉＯ３晶粒，对于水热法制备ＢａＴｉＯ３粉体，这是一种十分理想的前驱物．水热法制得的是立方相钙钛矿型ＢａＴｉＯ３晶粒．升高温度使得晶粒晶胞常数减小，这种现象被认为是由于ＯＨ－进入晶格并形成一定形式的缺陷而造成的．
Much and much attention was given to the hydrothermal synthesis of ceramic powders, due to the well crystallized, weakly agglomerated ceramic powders with well sinterability can be prepared by this technique. The results of hydrothermal preparation of BaTiO3 fine powders were reported. The chemical form of the precursors on the phase composition, the size and the morphology of the products were found out. The higher the temperature, the higher the acidity and the greater the molar ratio of Ba/Ti in the precursor, the easier the formation of the perovskite type BaTiO3 crystallite. Hydrothermal reaction of the newly prepared Ti(OH)4 gel with the Ba(OH)2 solution produced highly crystallized, well dispersed perovskite type BaTiO3 crystallites with very fine(<100nm) particles. The newly prepared Ti(OH)4 gel turnes out to be a suitable precursor for the hydrothermal preparation of BaTiO3 fine powder. X-ray diffraction (XRD) of the hydrothermal BaTiO3 powders reveals a simple cubic perovskite structure. Above all, the lattice constant (a) decreases with the increase of the reaction temperature. These abnormal crystallographic features are assumed to result from lattice defects, due to the OH- incorporated in the perovskite lattice.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1995年第3期293-300,共8页
Journal of Inorganic Materials
基金
国家自然科学基金
关键词
水热法
钛酸钡
粉体
电子陶瓷
hydrothermal method
BaTiO_3 crystallite
precursor
reaction conditions
