García J, Sánchez M C, Subías G, Blasco J, Proietti M G
Instituto de Ciencia de Materiales de Aragón, C.S.I.C.-Universidad de Zaragoza, Spain.
J Synchrotron Radiat. 2001 Mar 1;8(Pt 2):892-4. doi: 10.1107/s0909049501000310.
The electronic state of Mn atoms in mixed valence manganites has been studied by means of X-ray absorption spectroscopy at the Mn K-edge. Higher resolution than in conventional measurements has been achieved by measuring the Mn Kbeta fluorescence line. We have found a unique resonance at the edge in the XANES spectra of intermediate composition RE1-xCa(x)MnO3 samples. The features of these XANES spectra do not depend on small changes in the local structure around the Mn atom. However, the spectra of the intermediate composition samples can not be reproduced by a linear combination of REMnO3 and CaMnO3 spectra. Accordingly, the electronic state of Mn atoms in these compounds can not be considered as a mixture of Mn3+ and Mn4+ pure states.
通过锰K边的X射线吸收光谱法研究了混合价态锰酸盐中锰原子的电子态。通过测量锰Kβ荧光线，实现了比传统测量更高的分辨率。我们在中间成分RE1-xCa(x)MnO3样品的XANES光谱的边缘发现了一个独特的共振。这些XANES光谱的特征不依赖于锰原子周围局部结构的微小变化。然而，中间成分样品的光谱不能通过REMnO3和CaMnO3光谱的线性组合来再现。因此，这些化合物中锰原子的电子态不能被视为Mn3+和Mn4+纯态的混合物。
