Three dimensional momentum space density of electrons in metals and their electronic Structure 金属中の電子の3次元運動量空間密度と電子的性質の関連

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著者

    • Abdul Hamid Alaa Salah アブドルハミド アラーサラー

書誌事項

タイトル

Three dimensional momentum space density of electrons in metals and their electronic Structure

タイトル別名

金属中の電子の3次元運動量空間密度と電子的性質の関連

著者名

Abdul Hamid Alaa Salah

著者別名

アブドルハミド アラーサラー

学位授与大学

筑波大学

取得学位

博士 (工学)

学位授与番号

甲第2101号

学位授与年月日

1999-03-25

注記・抄録

博士論文

Our goal in the present work is to study the momentum space density and Fermi surface on certain materials of interest using 2D-ACAR experiment. These materials are the divalent HCP structure metals Mg, Zn and Cd, the HCP structure metals of group IIIA Sc and Y, the HCP structure metals of group IVA Ti, Zr and Hf, FCC structure metals of group VIII Rh and Ir, the non-cuprate layered proveskite superconductor Sr2RuO4, and the layered dichalcogenides of group VB NbSe2. The measurements have been carried out using two experimental set-ups. In the first, a pair of 128 detectors has been used to construct the data covering 20 mrad × 20 mrad. In the second, a pair of 256 detectors has been used to construct the data covering 30 mrad × 30 mrad. From the measured 2D-ACAR spectra the three dimensional electron density in the momentum space p(P) has been reconstructed using the reconstruction technique based on Fourier transform. Some observations have been noticed from the reconstructed spectra. Firstly, the divalent HCP structure metals show distortions in upper part of their spectra. Those distortions have been observed and discussed in terms of Kahana-like enhancement and many body effects. Secondly, the metals of groups IIIA and IVA show Breaks in their spectra. Those breaks have been studied and interpreted in terms of the electronic configurations of the examined metals. Thirdly, the high momentum components (HMC's) have been observed in the spectra of the used elements. They are attributed to the Umklapp process. Fourthly, the effect of the strong signal d-like in the Fermi surface features in the elements of groups IIIA, IVA and VIII has been observed and discussed. Finally, in Ir spectra broadening has been observed and discussed in terms of its high absorption of γ-rays. The electron density in the wave vector space n(k) has been constructed, restricted within first Brillouin zone, using Locks, Crisp and West (LCW) folding procedure. Then, Fermi surfaces of the metals under investigations have been constructed. Moreover, the least square fitting method has been applied in the experimental results with respect to the theoretical ones to estimate the band's occupation. The results of Fermi surface for each group of materials will discuss below. Fermi surfaces of divalent HCP structure metals have been compared with (he free electron model and with that obtained from band structure calculation using linear muffin tin orbital (LMTO) and augmented plane wave method (APW) methods. They show agreement with that obtained from the free electron model. The absence of some sheets from the Fermi surface of Mg, Zn and Cd has been interpreted in terms of the experimental resolution. Fermi surfaces of the metals of group IIIA have been compared with the free electron model and with the band structure calculation using cellular and APW methods. And the Fermi surfaces of the metals of group IVA have been compared with the free electron model, and the band structures calculation using APW and linear combination of atomic orbital (LCAO) methods. The Fermi surfaces of Sc, Y, Ti and Zr show agreement with that obtained from APW method, while the Fermi surface of Hf shows agreement with that obtained from relativistic RAPW method. Fermi surfaces of Rh and Ir have been compared with the RAPW and LCAO methods. These Fermi surfaces show good agreement with the band structure calculation using RAPW method. Fermi surface of Sr2RuO4 has been obtained and compared with that calculated using the local-density approximation (LDA) method. The present results show good agreement with the band structure calculation. Fermi surface of NbSe2 has been compared with the band structure calculation using APW method. The difference of the dimension of the hole surface around Γ-A axis in the Fermi surface of NbSe2 has been explained in terms of the non uniformity of the positron wave function. The deviations of the Fermi surface dimensions from that obtained by the band structure calculation have been explained in terms of the present experimental resolution. As regards, while the divalent HCP structure metals show good agreement with the free electron model, deviation from it obtains for the other elements.

Thesis (Ph. D. in Engineering)--University of Tsukuba, (A), no. 2101, 1999.3.25

目次

  1. Acknowledgment / (0003.jp2)
  2. List of symbols / p1 (0005.jp2)
  3. List of Figure / p2 (0006.jp2)
  4. Table of contents / p9 (0013.jp2)
  5. Abstract / p13 (0017.jp2)
  6. CHAPTER I General Introduction / (0020.jp2)
  7. 1.1 Historical Introduction / p2 (0021.jp2)
  8. 1.2 Critique of the band structure calculation methods / p4 (0023.jp2)
  9. 1.3 Aim of the work / p6 (0025.jp2)
  10. Chapter II Theoretical Considerations / p8 (0027.jp2)
  11. II.1 2D-ACAR spectra N(Py,Pz) / p9 (0028.jp2)
  12. II.2 Electron density in the momentum space p(P) / p12 (0031.jp2)
  13. II.3 High Momentum Components HMC's / p15 (0034.jp2)
  14. II.4 LCW(Loucks,Crisp and West)folding procedure / p17 (0036.jp2)
  15. II.5 The enhancement effect / p20 (0039.jp2)
  16. CHAPTER III Experimental set-up,Data analysis and Error estimation / p21 (0040.jp2)
  17. III.1 Experimental set up / p22 (0041.jp2)
  18. III.2 Data Analysis / p31 (0050.jp2)
  19. III.3 Error Estimation / p39 (0058.jp2)
  20. CHAPTER IV Results and Discussions / (0061.jp2)
  21. IV.1 The divalent HCP structure metals Magnesium(Mg), Zinc(Zn)and Cadmium(Cd) / p43 (0062.jp2)
  22. IV.2 HCP structure metals of valence three Scandium Sc and Yttrium Y / p68 (0087.jp2)
  23. IV.3 HCP structure metals of group IVA Titanium Ti,Zirconium Zr and Hafnium Hf / p85 (0104.jp2)
  24. IV.4 FCC structure metals of group VIII Rhodium Rh and Indium Ir / p106 (0125.jp2)
  25. IV.5 The non-cuprate layered perovskite superconductor Sr₂RuO₄ / p120 (0139.jp2)
  26. IV.6 The layered dichalcogenides of group VB NbSe₂ / p130 (0149.jp2)
  27. Conclusions / p138 (0157.jp2)
  28. References / p143 (0162.jp2)
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  • NII論文ID(NAID)
    500000185607
  • NII著者ID(NRID)
    • 8000000185889
  • DOI(NDL)
  • 本文言語コード
    • jpn
  • NDL書誌ID
    • 000000349921
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    • 機関リポジトリ
    • NDL ONLINE
    • NDLデジタルコレクション
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