   Influence of Na doping and sintering temperature on increasing Bi2Sr2CaCu2O8 superconducting phase content in powder-form materialsRahier, Sébastien  ; ; Cloots, Rudi et alin Materials Letters (2006), 60(3), 298-300 This paper proposes a systematic way to explore the effects of Na on Bi-2212 phase formation. The influence of sodium metal is correlated with the 2212 fraction formed in the sample. The effect on the ... [more ▼] This paper proposes a systematic way to explore the effects of Na on Bi-2212 phase formation. The influence of sodium metal is correlated with the 2212 fraction formed in the sample. The effect on the sintering temperature and the importance of the substitution site is studied. Samples are characterized by X-ray diffraction analysis (XRD). Results clearly show that the 2212 phase content is enhanced and sintering temperatures can be lowered with regard to the undoped samples. (c) 2005 Elsevier B.V. All rights reserved. [less ▲] Detailed reference viewed: 11 (1 ULg)Chemical interactions between Bi2Sr3CaO7(Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy))Rahier, Sébastien ; Lafort, Adeline ; Henrist, Catherine et alin Superconductor Science & Technology (2006), 19(1), 39-43 The chemical interactions between Bi2Sr3CaO7 (Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy)) at 965 degrees C were investigated by means of: (i) an interdiffusion couple and (ii) layers deposited by dip ... [more ▼] The chemical interactions between Bi2Sr3CaO7 (Bi-2310) and Bi2Sr2Ca0.8Dy0.2Cu2O8 (Bi-2212(Dy)) at 965 degrees C were investigated by means of: (i) an interdiffusion couple and (ii) layers deposited by dip coating on oxidized nickel Substrates. The samples were characterized by optical and electron microscopies, energy-dispersive x-ray (EDX) analysis and x-ray diffraction. It turns out that at the peritectic temperature Of Bi-2212(Dy), the Bi-2310 phase reacts with the liquid phase resulting from the peritectic decomposition of the Bi-2212(Dy) phase. Dissolution of Bi-2310 leads to an enrichment in Sr and an impoverishment in Cu of the liquid phase, resulting in a shift of the composition of the insoluble phase towards the Ca-rich end of the (Ca, Sr)O Solid Solution. [less ▲] Detailed reference viewed: 63 (19 ULg) Superconducting properties of magnetically textured Dy doped Bi-2212 nickel tapesFagnard, Jean-François ; Rahier, Sébastien ; et alin Andreone, A. (Ed.) Applied Superconductivity 2003 (Proceedings of the 6th European Conference on Applied Superconductivity) (2004) This communication aims at reporting the superconducting properties of Dy-doped Bi-2212/NiO/Ni tapes prepared by a dip-coating process from an inorganic gel. The Bi-2212 is recrystallized at 965°C in ... [more ▼] This communication aims at reporting the superconducting properties of Dy-doped Bi-2212/NiO/Ni tapes prepared by a dip-coating process from an inorganic gel. The Bi-2212 is recrystallized at 965°C in presence of an external 1.2 T magnetic induction. The precursor gel, the temperature and the thermal treatment duration are optimized regarding the microstructure The resulting tape samples are characterized by electrical resistance and I-V curves. The presence of secondary phases, such as Bi-2201, is reduced after a 750°C annealing but Ni diffusion limits the critical current density of the as-obtained tapes. The magnetic critical current density measured on textured Dy-doped Bi-2212 monoliths, obtained with the same type of texturation process, but showing no Ni contamination, is found to be about 30 times larger than the critical current density of the tapes. [less ▲] Detailed reference viewed: 50 (16 ULg) |
||
