K_2NiF_4型希土复合氧化物Eu_(2-x)Sr_xNiO_(4+δ)的合成、结构及还原性能  

PREPARATION, CRYSTAL STRUCTURE AND REDUCIBILITY OF K 2NiF 4 TYPE OXIDES Eu 2-x Sr xNiO 4+δ

作　　者：楼辉[1] 徐元植[1] 陈平[2] 葛玉平[2] 吕光烈[2] 马福泰[2] 

机构地区：[1]浙江大学化学系 [2]杭州大学化学系

出　　处：《无机化学学报》1999年第2期158-164,共7页Chinese Journal of Inorganic Chemistry

基　　金：浙江省自然科学基金

摘　　要：利用柠檬酸配合物分解法合成了单相的Ｋ２ＮｉＦ４型希土复合氧化物Ｅｕ２－ｘＳｒｘＮｉＯ４＋δ（０．５≤ｘ≤１．２），粉末Ｘ射线衍射分析表明，在ｘ为０．６～０．７的范围内，物相从空间群为Ｆｍｍｍ的正交相转变成空间群为Ｉ４／ｍｍｍ的四方相，随着Ｓｒ２＋的加入，部分Ｎｉ２＋转变为Ｎｉ３＋，其转变量与理论值接近。反映结构稳定性的高温还原峰温与晶胞参数ｃ有对应关系，表明化合物的结构稳定性取决于ＡＯ层与ＡＢＯ３层的层间距离。K 2NiF 4 type compounds Eu 2-x Sr xNiO 4+δ (0.5≤ x ≤1.2) have been prepared by a citric acid complex decomposition method. The powder X ray diffraction data showed that there is a crystal system transformation from orthorhombic Fmmm to tetragonal I4/mmm at around x =0.6 to 0.7. The valences state of nickel in the samples are increased with the Sr substitution, which does not deviate much from theoretical data. The variation of T max,h , in TPR profiles, is opposite to the cell parameter c with increasing x , which means that the structural stability of Eu 2-x Sr xNiO 4+ δ is related to the distance between the layers of perovskite and rocksalt.

关 键 词：铕 锶 镍 K2NiF4型 结构 复合氧化物 稀土 

分 类 号：O614.338[理学—无机化学] O614.232[理学—化学]