Electronic structure of ZrTiO4 and HfTiO4: Self-consistent cluster calculations and X-ray spectroscopy studies
Electronic structure of ZrTiO4 and HfTiO4: Self-consistent cluster calculations and X-ray spectroscopy studies
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DOI：
10.1016/j.jpcs.2010.11.003
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发表时间：
2011-02
影响因子：
4
通讯作者：
A. Lavrentyev;B. V. Gabrelian;P. N. Shkumat;I. Nikiforov;T. Bondarenko;E. Kopylova;O. Khyzhun;M. Karpets;J. Rehr
中科院分区：
文献类型：
--
作者：
A. Lavrentyev;B. V. Gabrelian;P. N. Shkumat;I. Nikiforov;T. Bondarenko;E. Kopylova;O. Khyzhun;M. Karpets;J. Rehr
使用FEFF8代码中包含的自洽簇方法计算了zrtio4和hftio4钛酸盐组成原子的总态和部分态密度。计算结果揭示了两种钛酸盐的电子结构的相似性，并表明所考虑的化合物的价带主要是o2p态的贡献。这些州贡献了整个价带区；然而，它们的最大贡献出现在波段的上部。价带区的其他重要贡献者是zrtio4中的Ti 3d和Zr 4d态以及HfTiO4中的Ti 3d和Hf 5d态。上述所有类d态分布在钛酸盐的整个价带区；然而，Ti 3d态的最大贡献出现在价带的上部，而Zr 4d （Hf 5d）态的贡献则出现在价带的中部。FEFF8计算表明，zrtio4和hftio4的导带底部主要由Ti 3d <s:2>态贡献，Zr 4d /Hf 5d和o2p态也有较小贡献。为了验证上述FEFF8数据，我们测量了主要代表o2p、Ti 3d和Zr 4d态能量分布的x射线发射带，并在普通能量尺度上进行了比较。这些实验数据与zrtio4和hftio4钛酸盐电子结构的理论FEFF8结果一致。此外，还记录了所研究钛酸盐组成原子的x射线光电子价带和核能级光谱。
Total and partial densities of states of the constituent atoms of ZrTiO4and HfTiO4titanates have been calculated using a self-consistent cluster method as incorporated in the FEFF8 code. The calculations reveal the similarity of the electronic structure of both titanates and indicate that the valence band of the compounds under consideration is dominated by contributions of O 2p states. These states contribute throughout the whole valence-band region; however their maximum contributions occur in the upper portion of the band. Other significant contributors in the valence-band region are Ti 3d and Zr 4d states in ZrTiO4and Ti 3d and Hf 5d states in HfTiO4. All the above d-like states contribute throughout the whole valence-band region of the titanates; however maximum contributions of the Ti 3d states occur in the upper portion, whilst those of the Zr 4d (Hf 5d) states are in the central portions of the valence band. The FEFF8 calculations render that the bottom of the conduction band of ZrTiO4and HfTiO4is dominated by contributions of Ti 3d⁎states, with also smaller contributions of Zr 4d⁎/Hf 5d⁎and O 2p⁎states. To verify the above FEFF8 data, the X-ray emission bands, representing the energy distributions of mainly O 2p, Ti 3d and Zr 4d states, were measured and compared on a common energy scale. These experimental data are found to be in agreement with the theoretical FEFF8 results for the electronic structure of ZrTiO4and HfTiO4titanates. Additionally, X-ray photoelectron valence-band and core-level spectra were recorded for the constituent atoms of the titanates under study.