摘要
合成了一系列钙钛矿复合氧化物La_(1-x)M_(?)CoO_3(M=Ca,Sr),并用XPS研究了LaCoO_3中的La^(3+)部分被Ca^(2+)或Sr^(2+)取代后表面状态的变化。由XPS的O_(10)谱图拟合得到的吸附氧O(2)百分数与取代量x呈现规律性变化。对Ca_(2p)与Sr_(3d)谱图也进行峰拟合处理,其中结合能较高的Sr(2)、Ca(2)可指认为周围有氧离子缺位物种。Ca(2)或Sr(2)百分数与吸附氧百分数的关系可用取代后表面状态的变化来解释。
A series of La1-xMxCoO3 (M = Ca,Sr) perovskite oxides have been synthesized and the change of surface states after the substitution of La3+ ion in LaCoO3 with Ca2+ or Sr2+ ion have been investigated by XPS technique. It is shown that the percentage of adsorbed oxygen obtained in the peak fitting of O1s spectra is regularly varied with the substitution content x. The peak fitting of Ca2p, and Sr3d spectra has been performed and Ca(2) and Sr(2) may be assigned to the situation that there exist vacancies of oxygen surrounding them. The relationship between the percentage of Ca(2) or Sr (2) and the percentage of absorbed oxygen can be adoptd to explain the surface state change after substitution. Therefore, we reasonably assume that the substitution of Sr2+ causes an increase in vacancy of oxygen, however, the substitution of Ca2+ causes an opposite result.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1990年第11期1227-1231,共5页
Chemical Journal of Chinese Universities
关键词
钙钛矿
复合氧化物
氧离子缺位
XPS, Perovskite oxide, Oxygen anion vacancies
