Evidence of Eu2+ 4f electrons in the valence band spectra of EuTiO3 and EuZrO3
Evidence of Eu2+ 4f electrons in the valence band spectra of EuTiO3 and EuZrO3
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DOI：
10.1063/1.4761933
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发表时间：
2012-10
影响因子：
3.2
通讯作者：
T. Kolodiazhnyi;M. Valant;J. Williams;M. Bugnet;G. Botton;N. Ohashi;Y. Sakka
中科院分区：
文献类型：
--
作者：
T. Kolodiazhnyi;M. Valant;J. Williams;M. Bugnet;G. Botton;N. Ohashi;Y. Sakka
我们报告了两个基于EU2+的钙钛矿，Eutio3和Euzro3的光条间隙和价电子结构，如弥漫性光学散射，电子能量损耗光谱和价频段X射线光电部光谱所揭示。数据表明，与第一原理研究一致，其中狭窄的EU 4F7电子带形成了价带结构的顶部。 O 2P谱带显示了与Ba（SR）Tio3钙钛矿相似的特征，但它被转移到更高的结合能。与基于SR的类似物相比，EU2+ 4F7频段的外观是标题化合物中光节间隙狭窄的原因。
We report on optical band gap and valence electronic structure of two Eu2+-based perovskites, EuTiO3 and EuZrO3 as revealed by diffuse optical scattering, electron energy loss spectroscopy, and valence-band x-ray photoelectron spectroscopy. The data show good agreement with the first-principles studies in which the top of the valence band structure is formed by the narrow Eu 4f7 electron band. The O 2p band shows the features similar to those of the Ba(Sr)TiO3 perovskites except that it is shifted to higher binding energies. Appearance of the Eu2+ 4f7 band is a reason for narrowing of the optical band gap in the title compounds as compared to their Sr-based analogues.