复合稀土氧化物和硫氧化物超细粉的制备和结构

Preparation and Structure of Monodispersed superfine Particles of Complex Rare Earth Oxides and Oxysulfides

以脲为水解试剂，采用强迫水解法制备了（Ｙ，Ｃｄ，Ｃｄ，Ｅｕ）２Ｏ３、（Ｙ，Ｔｂ）２Ｏ３、（Ｙ，Ｇｄ，Ｅｕ）２Ｏ２Ｓ和（Ｙ，Ｔｂ）２Ｏ２Ｓ等一系列复合稀土氧化物和硫氧化物超细粉，研究了热分解反应的机理以及产物的结构和性能。

Monodispersed fine spherical particles(～100 nm)of complex rare earth hydroxy carbonates are prepared by hydrolizing mixed rare earth nitrates solution at elevated tempera ture in the presence of urea. By calcining the hydroxycarbonates at moderate temperature,complex rare earth sesquioxides(～70 nm)of C- type can be obtained.The mechnism of the decomposition of hydroxycarbonate at different temperatures have been verified to proceed through monoxydicarbonate, dioxymonocarbonate to sesquioxide of body- Centered structure by DTA,TGA,XRD and HREM. The experimental EDP diagrams of complex rare earth sesquioxides have been identified with those of calculated C-type structure. Complex rare earth oxysulfides of hexagonal structure can be prepared by firing a blend of complex rare earth hydroxycarbonate,S, Na2CO3 and KH2PO4 at 1000℃.