| Item type |
学位論文 / Thesis or Dissertation(1) |
| 公開日 |
2023-03-30 |
| タイトル |
|
|
タイトル |
蛍光X線ホログラフィーによるランタンをドープしたチタン酸ストロンチウムの局所構造の研究 |
| タイトル |
|
|
タイトル |
Study on the Local Structure of Lanthanum-Doped Strontium Titanate by Means of X-Ray Fluorescence Holography |
|
言語 |
en |
| 言語 |
|
|
言語 |
jpn |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
lanthanum-doped strontium titanate |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
structural phase transition |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
electron conductivity |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
X-ray fluorescence holography |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
local structure analysis |
| 資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_db06 |
|
資源タイプ |
doctoral thesis |
| アクセス権 |
|
|
アクセス権 |
open access |
|
アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
| 著者 |
戎, 佳宏
Ebisu, Yoshihiro
|
| 抄録 |
|
|
内容記述タイプ |
Abstract |
|
内容記述 |
Strontium titanate SrTiO3 of the cubic perovskite structure is a representative of dielectric crystals. Doping lanthanum atoms into SrTiO3 yields conductive mixed crystals Sr1-xLaxTiO3. Excess electrons are doped into the conduction band composed of the Ti-3d state, and then Ti4+ turn into Ti3+. Such electron-conductive perovskite materials have high utility value in thermoelectric materials of high Seebeck coefficients, conductive substrates of high-TC superconductor films and so on. Sr1-xLaxTiO3 also shows the high structural phase transition temperature and the large saturated spontaneous rotation angle of the TiO6 octahedra. In the present study, we carried out X-ray fluorescence holography using the La Lγ1 ray (La Lγ1 XFH) on Sr0.95La0.05TiO3 and obtained the three-dimensional local structure around the La atom at 297 K. The experimentally obtained X-ray fluorescence holograms and the power spectra of the holographic oscillations were reproduced by the atomic cluster model having the radius of 200 Å. The experimentally obtained local structure showed that the La atoms were doped into the Sr sites of the cubic perovskite structure of SrTiO3 and the La-Sr(La) lattice distance was slightly larger than the averaged lattice parameter of Sr0.95La0.05TiO3. The local structure around the La atom plays significant roles in the electron-conduction and the high phase transition temperature through the softenings of the optic and the elastic phonons, respectively. Based on the present study, we proposed the La Lγ1 XFH study on the electron-conduction and the structural phase transition of Sr0.95La0.05TiO3 nanocrystals. |
| 学位名 |
|
|
学位名 |
博士（工学）（Doctoral Dissertation） |
| 学位授与機関 |
|
|
|
学位授与機関識別子Scheme |
kakenhi |
|
|
学位授与機関識別子 |
35403 |
|
|
学位授与機関名 |
広島工業大学（Hiroshima Institute of Technology) |
| 学位授与年月日 |
|
|
学位授与年月日 |
2019-03-16 |
| 学位授与番号 |
|
|
学位授与番号 |
甲第17号 |
| フォーマット |
|
|
内容記述タイプ |
Other |
|
内容記述 |
application/pdf |
| 著者版フラグ |
|
|
出版タイプ |
VoR |
|
出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
17.pdf (36.3 MB)
