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Materials Science and Engineering

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Missouri University of Science and Technology

Series

2008

Barium compounds

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Yba₂Cu₃O₆₊ₓ, F. Stercel, T. Egami, H. A. Mook, M. Yethiraj, M. Arai, C. Frost, Fatih Dogan, J. H. Chung Jan 2008

Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Yba₂Cu₃O₆₊ₓ, F. Stercel, T. Egami, H. A. Mook, M. Yethiraj, M. Arai, C. Frost, Fatih Dogan, J. H. Chung

Materials Science and Engineering Faculty Research & Creative Works

An inelastic pulsed neutron scattering study was performed on the dependence of the dispersion and spectral intensity of the in-plane Cu-O bond-stretching LO phonon mode on doped charge density. The measurements were made in the time-of-flight mode with the multiangle position sensitive spectrometer of the ISIS facility on single crystals of YBa2Cu3O6+x (x=0.15, 0.35, 0.6, 0.7, and 0.95). The focus of the study is the in-plane Cu-O bond-stretching LO phonon mode, which is known for strong electron-phonon coupling and unusual dependence on composition and temperature. It is shown that the dispersions for the samples with x=0.35, 0.6, and 0.7 are …


Anomalous Magnetic Ordering In Prba₂Cu₄O₈ And Cmba₂Cu₃O₇, H. A. Blackstead, M. P. Smylie, William B. Yelon, Qingsheng Cai, Mehmet Kahveci Jan 2008

Anomalous Magnetic Ordering In Prba₂Cu₄O₈ And Cmba₂Cu₃O₇, H. A. Blackstead, M. P. Smylie, William B. Yelon, Qingsheng Cai, Mehmet Kahveci

Physics Faculty Research & Creative Works

A review of temperature-dependent magnetization data for nonsuperconducting PrBa2Cu4O8 and CmBa2Cu3O7 suggests that the failure of each to superconduct is related to the presence of Pr and Cm on their respective Ba sites. This defect is manifested, in each case, by short c-axis lattice parameters and anomalous high-temperature magnetic ordering which has been incorrectly attributed to ordering of the entire magnetic sublattice. Instead, it is shown that the anomalous high-temperature ordering as seen in the magnetization data is consistent with the ordering of magnetic ions substituted on the Ba site.