Analysis of Electron Conduction Band of Electro-conductive Ceramics by X-ray Absorption

本文主要用X射线吸收法分析了MgIn_2O_3和BaPb_Bi_xO_3导电陶瓷的电子导带<4-delta><1-x><3-delta>。前者是新近发现的透明导体，后者是经典的超导氧化物.首次成功地制备了MgIn_2O_3透明薄膜<4-delta>。不仅在应用方面，而且在基础研究方面都可以取得重大进展.测量了MgIn_2O_3薄膜的X射线吸收<4-delta>，在In-L吸收边观察到边前峰。结果表明，导带主要由In 5s轨道组成。3.通过<1-x><3.00>X射线衍射和电子电导测量，揭示了BaPb_ Bi_xO_3晶体结构与电子导电行为的关系。测量的X射线吸收光谱与导带的电子结构相一致，从上述关系式推导出导带的电子结构.为了阐明影响 ...更多信息 用<0.75><0.25><3-delta>X射线吸收谱仪测量了不同氧含量的样品的电子能带结构。X射线吸收的线形变化不大，表明电子载流子浓度和组成导带的轨道的变化可以忽略不计.除X射线吸收外，还测量了BaPb_ Bi_ O_的热天平、高温电子电导和塞贝克系数<0.75><0.25><3-delta>。结果表明，氧的缺乏是散射中心，而不是电子载流子的产生。这些结果与X射线吸收光谱法的结果一致.通过<0.75><0.25><3-delta>测量Seebeck系数随温度的变化关系，揭示了BaPb_ Bi_ O_2中大迁移率电子与低迁移率空穴共存的现象。这些信息可能有助于超导转变机制的分析。少

Electron conduction bands of electro-conductive ceramics, such as MgIn_2O_<4-delta> and BaPb_<1-x>Bi_xO_<3-delta>, were analyzed mainly by X-ray absorption. The former is the newly discovered transparent conductor, and the latter is classical superconducting oxide.1. Transparent thin film of MgIn_2O_<4-delta> was successfully prepared for the first time. Large progress not only for application but for fundamental research could be made.2. X-ray absorption of the thin film of MgIn_2O_<4-delta> was measured and pre-edge peak was observed in In-L absorption edge. It was revealed that conduction band consisted mainly of In 5s orbital.3. Relationship between crystal structure and electronic conduction behavior of BaPb_<1-x>Bi_xO_<3.00> was revealed by X-ray diffraction and electron conduction measurement. Measured X-ray absorption spectroscopy consisted with electronic structure of conduction band, which was deduced from the above clarified relationship.4. In order to clarify the influence … More of oxygen deficiency on electronic band structure of BaPb_<0.75>Bi_<0.25>O_<3-delta>, X-ray absorption spectroscopes were measured on the samples with various oxygen deficiency, delta. There were little variation in line shape of X-ray absorption by delta, which suggested that variations of electron carrier concentration and orbitals which composed the conduction band were negligible.5. Besides X-ray absorption, thermobalance, electronic conduction at high temperature and Seebeck coefficient of BaPb_<0.75>Bi_<0.25>O_<3-delta> were measured. It was revealed that oxygen deficiency worked as scattering center rather than electron carrier generation. These results consisted with that of X-ray absorption spectroscopy.6. Coexistence of electrons with large mobility and holes with low mobility in BaPb_<0.75>Bi_<0.25>O_<3-delta> was revealed from the measurement of temperature dependence of Seebeck coefficients. This information might be useful for the analysis of superconducting transition mechanism. Less