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  1. No Access

    Article

    Near-field photoconductivity imaging of a conjugated polymer blend

    We report combined scanning near-field optical microscopy (SNOM) and near-field photocurrent (NPC) imaging of a binary conjugated polymer blend. We find phase separation on a scale of about 5 μm, with a good c...

    R. Riehn, R. Stevenson, J. J. M. Halls, D. R. Richards… in MRS Online Proceedings Library (2011)

  2. No Access

    Article

    Managing the dispersal of ladybird beetles (Col.: Coccinellidae): Use of artificial honeydew to manipulate spatial distributions

    We tested whether large-scale distributions of aphidophagous ladybirds could be manipulated by localized application of artificial honeydew. In addition to enhancing local build-up of ladybird numbers (e.g., in a...

    E. W. Evans, D. R. Richards in BioControl (1997)

  3. No Access

    Article

    Chemistry and structural modulations in Bi2Sr2CuO6

    A series of samples along the composition lines Bi2+xSr2−xCuOy, and Bi2Sr2−xCuOy have been used to study the structural modulation, chemistry, and superconducting properties of pseudo-tetragonal Bi2Sr2CuO6 (2201)...

    Y. Shen, D. R. Richards, D. G. Hinks, A. W. Mitchell in Journal of Materials Research (1992)

  4. No Access

    Chapter and Conference Paper

    Phase Instability at the Maximum Tc in Oxide Superconductors: Phase Separation in La2CuO4+x, Nd2−xCexCuO4, and La2−xSrxCuO4

    Observation of similar behavior in three different superconducting oxides suggests that the maximum Tc is limited by phase instability. These conclusions are based on previously published neutron powder diffracti...

    J. D. Jorgensen, P. Lightfoot, Shiyou Pei… in Advances in Superconductivity III (1991)

  5. No Access

    Chapter

    Powder Neutron Diffraction Study of the Structural Phase Diagram of the Ba1−xKxBiO3 System

    In this article we present a brief report of recent work carried out to elucidate the phase diagram of the Ba1−xKxBiO3 system. A full account of this investigation will be published shortly.1

    Shiyou Pei, J. D. Jorgensen, D. G. Hinks… in Oxygen Disorder Effects in High-T … (1990)

  6. No Access

    Article

    Structural Phase Diagram and Superconducting Behavior of the Ba1-Xkxbio3 System

    We have determined the crystal structures of five phases in the Bal-xKxBiO3 system for 0≤x≤0.5 and 10K≤T≤473K. Superconductivity occurs only in a cubic perovskite phase with the maximum Tc at the transition to an...

    J. D. Jorgensen, Shiyou Pei, D. G. Hinks, B. Dabrowski… in MRS Online Proceedings Library (1989)

  7. No Access

    Article

    Evidence for Phonon-Mediated Coupling in Superconducting Ba0.6K0.4BiO3

    Superconducting Ba0.6K0.4BiO3, with a Tc of 30K, shows a large18O isotope effect which indicates that phonons are involved in the pairing mechanism. Infrared reflectivity measurements indicate a value for the sup...

    D. G. Hinks, B. Dabrowski, D. R. Richards… in MRS Online Proceedings Library (1989)

  8. No Access

    Article

    Superconducting and Structural Properties of the (Ba0.6K0.4) (Bi1-YSbY)O3 System

    Single-phase samples of (Ba1-xKx)(Bi1-xSby)O3 have been synthesized over a limited compositional range using a two-step procedure: high-temperature firing in a low oxygen partial pressure followed by low-temperat...

    B. Dabrowski, S. Pei, D. R. Richards, Y. Zheng… in MRS Online Proceedings Library (1989)

  9. No Access

    Article

    Composition of Superconducting La2CuO4+δ a Superconductor Doped by excess Oxygen Defects

    We have studied mixed-phase samples of bulk LazCuO4 using neutron powder diffraction, thermogravimetric analysis and resistivity measurements. Samples fired at 950°C and slowly cooled form in the K2NiF4 structure...

    B. Dabrowski, D. G. Hinks, J. D. Jorgensen… in MRS Online Proceedings Library (1989)

  10. No Access

    Chapter

    La2MO4+δ (M=Cu, Ni, Co): Phase Separation and Superconductivity Resulting from Excess Oxygen Defects

    The structural, superconducting and normal-state properties of La2MO4+δ (M=Cu, Ni, Co) were studied by neutron powder diffraction, thermogravimetric analysis and resistivity measurements. La2CuO4+δ was found to u...

    B. Dabrowski, J. D. Jorgensen, D. G. Hinks… in Superconductivity and Applications (1989)

  11. Article

    Erratum: The oxygen isotope effect in Ba0.625K0.375BiO3

    Nature 335, 419-421 (1988). THE correct version of Fig. 16 is shown below.

    D. G. Hinks, D. R. Richards, B. Dabrowski, D. T. Marx, A. W. Mitchell in Nature (1988)

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  12. No Access

    Article

    The oxygen isotope effect in Ba0.625K0.375BiO3

    The nature of the superconducting pairing mechanism in the high-temperature superconducting oxides is still an open question. Shortly after the discovery of these materials, several groups began an intensive s...

    D. G. Hinks, D. R. Richards, B. Dabrowski, D. T. Marx, A. W. Mitchell in Nature (1988)

  13. No Access

    Article

    Synthesis, structure and superconductivity in the Ba1−xKxBiO3−y system

    The recent discovery of superconductivity near 30 K in Ba1−xKxBiO3−y (x≈0.4)1,2 is remarkable for two reasons. It is the first copper-free oxide superconductor that has a transition temperature (Tc) above that fo...

    D. G. Hinks, B. Dabrowski, J. D. Jorgensen, A. W. Mitchell, D. R. Richards… in Nature (1988)