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Blanco, M. C., D. G. Franco, Y. Jalit, E. V. Pannunzio Miner, G. Berndt, A. Paesano Jr., G. Nieva, and R. E. Carbonio. "Synthesis, magnetic properties and Mössbauer spectroscopy for the pyrochlore family Bi2BB′O7 with B=Cr and Fe and B′=Nb, Ta and Sb." Physica B: Condensed Matter 407, no. 16 (2012): 3078–3080.
Abstract: The samples Bi2BB′O7, with B=Cr and Fe and B′=Nb, Ta and Sb were prepared by solid state method. The crystallographic structure was investigated on the basis of X-ray powder diffraction data. Rietveld refinements show that the crystal structure is cubic, space group Fd-3m. The Bi3+ cation on the eight-coordinate pyrochlore A-site shows displacive disorder, as a consequence of its lone pair electron conï¬guration. There is also a considerable A-site disorder shown by Rietveld Analysis and confirmed in the case of the iron containing samples with Mössbauer spectroscopy. The magnetic measurements show paramagnetic behavior at all temperatures for the Cr oxides. The Fe pyrochlores show antiferromagnetic order around 10 K.
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Decca, R. S., H. D. Drew, B. Maiorov, J. Guimpel, and E. J. Osquiguil. "Inducing superconductivity at a nanoscale: Photodoping with a near- field scanning optical microscope." Journal of Microscopy 194, no. 2-3 (1999): 407–411.
Abstract: The local modification of an insulating GdBa2Cu3O6.5 thin film, made superconducting by illumination with a near-field scanning optical microscope (NSOM), is reported. A 100-nm aperture NSOM probe acts as a sub- wavelength light source of wavelength ?(exc)=480-650 nm, locally generating photocarriers in an otherwise insulating GdBa2-Cu3O6.5 thin film. Of the photogenerated electron-hole pairs, electrons are trapped in the crystallographic lattice, defining an electrostatic confining potential to enable the holes to move. Reflectance measurements at ? = 1.55 ?m at room temperature show that photocarriers can be induced and constrained to move on a ?? 200 nm scale for all investigated ?(exc). Photogenerated wires present a superconducting critical temperature T(c) = 12 K with a critical current density J(c) = 104 A cm-2. Exploiting the flexibility provided by photodoping through a NSOM probe, a junction was written by photodoping a wire with a narrow (? 50 nm) under-illuminated gap. The strong magnetic field modulation of the critical current provides a clear signature of the existence of a Josephson effect in the junction.
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Gil, D. M., J. Guimpel, A. Paesano Jr., R. E. Carbonio, and M. I. Gómez. "Y[Fe1−xCox(CN)6]·4H2O (0 ⩽ x ⩽ 1) solid solutions: Synthesis, crystal structure, thermal decomposition and spectroscopic and magnetic properties." Journal of Molecular Structure 1015 (2012): 112–117.
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Nakamura, O., I. Chan, J. Guimpel, and I. Schuller. "New buffer layer for high?temperature superconducting ceramics on sapphire: LaBa2Cu3Oy/Ag bilayers." Applied Physics Letters 59, no. 10 (1991): 1245.
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Valenzuela, S. O., B. Maiorov, E. Osquiguil, and V. Bekeris. "Elastic-to-plastic crossover below the peak effect in the vortex solid of YBa2Cu3O7 single crystals." Physical Review B – Condensed Matter and Materials Physics 65, no. 6 (2002): 605041–605044.
Abstract: We report on transport and ac susceptibility studies below the peak effect in twinned YBa2Cu3O7 single crystals. We find that disorder generated at the peak effect can be partially inhibited by forcing vortices to move with an ac driving current. The vortex system can be additionally ordered below a well-defined temperature where elastic interactions between vortices overcome pinning-generated stress and a plastic-to-elastic crossover seems to occur. The combined effect of these two processes results in vortex structures with different mobilities that give place to history effects.
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