Analysis of Electron Conduction Band of Electro-conductive Ceramics by X-ray Absorption
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants|
Inorganic materials/Physical properties
|Research Institution||The University of Tokyo|
HASHIMOTO Takuya The University of Tokyo, College of Arts and Sciences, Research Associate, 教養学部, 助手 (20212136)
|Project Period (FY)
1993 – 1994
Completed(Fiscal Year 1994)
|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1994 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1993 : ¥1,200,000 (Direct Cost : ¥1,200,000)
|Keywords||BaPb_<1-x>Bi_xO_<3-delta> / Oxygen deficiency / MgIn_2O_4 / X-ray absorption / Thermopower / Thermobalance / Electronic structure / Electronic conductivity / BaPb_<1-X>Bi_XO_<3-δ> / MgIn_2O_<4-δ> / 高温熱天秤 / BaPb_<1-X>Bi_xO_<3-σ> / MgIn_2O_<4-σ> / 薄膜合成|
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
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
Research Products (26results)