共沉淀法制备铌铁酸铅超细粉体

LEAD FERRITE NIOBATE PEROVSKITE FINE POWDERS PREPARED BY COPRECIPITATION METHOD

用络合法将Nb2O5转化成可溶性的铌盐,作为铌源,用共沉淀法合成了超细钙钛矿相Pb(Fe1/2Nb1/2)O3粉体。实验中以氨水作为沉淀剂,通过调节溶液的pH值,使铌、铁、铅等金属元素同时以氢氧化物的形式析出。X射线衍射表明:前驱体经400°C的低温煅烧已经出现钙钛矿相;当煅烧温度提高至800°C时,前驱体全部转化为钙钛矿相。扫描电镜观察表明:其颗粒形状呈立方体,尺寸为300～500nm。

Fine powders of pure perovskite Pb（Fe1/2Nb1/2）O3 （PFN） were prepared successfully by the coprecipitation method and using the raw material of Nb2O5 changed into a water-soluble species through the chemical chelation as the Nb source. Aqueous ammonia was used to modulate the pH of the solution to realize the simultaneous precipitations of hydroxides of Nb^5＋, Fe^3＋, and Pb^2＋ ions. The experiment results show that the perovskite phase occurs at a low temperature of 400℃ in the calcination of the precipitation product. X-ray diffraction and Raman scattering spectra results show that pure perovskite PFN powder was synthesized at 800℃. Scanning electron microscopy observation shows that the powder has a cube-like shape and nanoscale grain size of 300-500 nm