复合氧化物LaMn_(1-x)Fe_xO_3(x=0-1)的XPS研究

X-Ray Photoelectron Spectroscopy Study of LaMn_(1-x)Fe_xO_3 (x=0-1) Oxides

用XPS方法研究了具有ABO3结构的LaMn1-xFexO3（x＝0－1）氧化物的氧化还原性能、表面组成和吸附氧种．样品经还原和再氧化处理后，Mn2p和Fe2p结合能的变化对Fe和Mn之间发生的氧化还原提供了明显的证据．可表示如下：Me4＋＋Fe（3－δ）→Mn（4－δ）＋＋Fe3＋通过计算机用三种氧物种（OⅠ，OⅡ和OⅢ）对O1s峰进行拟合，确定了每种氧物种的状态．同时，以氧物种含量随还原、再氧化的变化，确定了发生在表面上的氧化还原反应同OⅠ和OⅡ吸附氧物种有关．在此基础上，对吸附位与氧之间的电子转移过程进行了讨论．

The redox potential, surface composition and oxygen species of a series of complex okides LaMn1-xFexO3 (x=0-1) having perovskite structure (ABO3) have been investigated by means of XPS. The variation of binding energies referring to Mn2p and Fe 2p under different treatment offerred an obvious evidence of redox between Mn and Fe,which could be expressed as Mn4+ + Fe(3-δ)+→Mn(4-δ)+ + Fe3+. Through computer fit three kinds of adsorbed oxygen species (OⅠ, OⅡ, OⅢ) have been evaluated based on the XPS spectra of O1s. From the variation of contents of different oxygen species, it could be concluded that the redox occuring in the surface might be related with the adsorbed oxygen species OⅠ and OⅡ, furthermore the possibility of transfer of electron between adsorption site and oxygen was also discussed.