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.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
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
关键词
铕
锶
镍
K2NiF4型
结构
复合氧化物
稀土
K 2NiF 4
type structure\ \ \ rate earth complex oxides\ \ \ X ray powder diffraction
