Search Results - (Author, Cooperation:C. Draxl)

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  1. 1
    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Ambrosch-Draxl, C. ; Abt, R. ; Kouba, R.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0921-4534
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  3. 3
    Ambrosch-Draxl, C. ; Blaha, P. ; Schwarz, K.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0921-4534
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  4. 4
    Ambrosch-Draxl, C. ; Schwarz, K.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0038-1098
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  5. 5
    Staff View
    ISSN:
    0921-4534
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  6. 6
    Abt, R. ; Ambrosch-Draxl, C. ; Knoll, P.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0921-4526
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  7. 7
    Ambrosch-Draxl, C. ; Knoll, P.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0921-4526
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  8. 8
    Sherman, E.Ya. ; Ambrosch-Draxl, C.
    Springer
    Published 2002
    Staff View
    ISSN:
    1434-6036
    Keywords:
    PACS. 63.20.Kr Phonon-electron and phonon-phonon interactions – 74.25.Kc Phonons
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract: We consider changes in the electron-phonon coupling in high-T c cuprates caused by site-selective oxygen isotope substitution. Contrary to the total substitution, the site-selective replacement influences the coupling constant for each phonon mode due to the induced changes in the phonon eigenvectors. The relative changes for some modes can be larger than 100%. The measured properties sensitive to these changes are discussed.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  9. 9
    Sherman, E.Ya. ; Ambrosch-Draxl, C.
    Springer
    Published 2000
    Staff View
    ISSN:
    1434-6036
    Keywords:
    PACS. 63.20.Kr Phonon-electron and phonon-phonon interaction - 74.25.Jb Electronic structure - 74.25.Kc Phonons
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract: We consider in detail Raman scattering by vibration of the apical oxygen ions in the RBa2Cu3O7 superconducting cuprates. The scattering intensity is very sensitive to the ratio of diagonal and off-diagonal matrix elements of electron-phonon coupling, bandstructure, and carrier concentration. Our results show a large quantitative difference between the results of frozen-phonon and perturbational approach to the Raman process. The discrepancy becomes especially large when interband transitions to the states near the Fermi level are close to resonance with the incident light. The calculation of phonon-induced ion charge fluctuations shows an analogous discrepancy. The reason for these effects is the possibility of carrier redistribution between different parts of the Fermi surface arising in the frozen-phonon approximation. Our results show that Raman scattering in superconducting superlattices is very sensitive to the properties of the states near the Fermi level. For this reason experiments performed on the superlattices can help to resolve the discrepancy.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  10. 10
    Ambrosch-Draxl, C. ; Blaha, P. ; Schwarz, K.
    Springer
    Published 1990
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract The electric field gradients (EFGs) at all atomic positions of YBa2Cu3O7 and YBa2Cu3O6 are calculated on the basis of full potential linearized augmented plane wave calculations by an ab initio method. Cood agreement with experimental EFGs is found for all oxygen positions in YBa2Cu3O7 and the Cu1 position in both compounds, while for the Cu2 position in the superconductor the symmetry of the EFG agrees with experiment but the magnitude of our theoretical EFG is only half the experimental value. A small transfer of 0.07 electrons from d(x2−y2) to d(z2) symmetry would be sufficient to achleve agreement with experiment. Thus the underlying local density approximation is not perfect, but remains a very accurate method for describing ground state properties.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  11. 11
    Korzhavyi, P. A. ; Ambrosch-Draxl, C. ; Johansson, B.
    Springer
    Published 1999
    Staff View
    ISSN:
    1573-7357
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract With the aim of establishing a relationship between the electronic structure and the site occupancy within the Cu-O chains, we perform total energy calculations for the sub-stoichiometric compound Yba 2 Cu 3 O 6.5 for various patterns of vacancy ordering. Supercells containing up to four formula units are considered. The effective interactions of O(1) atoms are extracted from the total energies by means of the cluster expansion technique. The most stable configuration is found to be the experimentally observed ortho-II structure. This finding is confirmed by Monte-Carlo simulations for a rigid lattice using the pair interactions. Thermal disorder effects are studied. The influence of vacancy ordering on the total and partial densities of states is discussed.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses