La_2Ti_2O_7的合成与结构分析

The Synthesis Structure and Properties of Lanthanum Titanate(la_2Ti_2O_7)

本文用四氯化钛、三氧化二镧为原料,以氨水为碱性物质,用共沉淀法,在pH为8.5—10范围内,得到了镧和钛的氢氧化物共沉淀,经过滤、洗涤、干噪、并在1100℃灼烧1小时,得到La_2Ti_2O_7晶体。产品属单斜晶系,P_(21m)空间群。晶体具有类钙钛矿结构,其中钛以四面体同氧原子配位。扫描电镜观察,产品呈椭球形、粒度均匀,大小为0.2—0.5μm。差热结合X—射线分析表明、产品首先以非晶态出现,在850℃左右结晶。本文还就pH、灼烧温度、灼烧时间等对产品的影响作了详尽的研究。

This paper describes synthesis of La2Ti2O7by copptn.method.La2O3and TiCI4were usek as starting materials,with NH3 · H2O as precipitating agent.Nonerystal La2Ti2O7nH2O was prepared in aq.,then,crystal La2Ti2O7can be obtained by calcining at 1100℃ for Ihr By IR spectro anal,the coordination of Ti by O atoms is tetrahedral.DTA and X-ray anal,identified that La2Ti2O7crystallizes at 845℃ .Electron mieroscope anal.,the particle size of the La2Ti2O7was 0.2-0.5um.