BSCCO

The most widely used development in HTS wire production is tlie powder-in-tube procedure with BSCCO ceramic materials. In this procedure very fine HTS powder, placed inside of a hollow silver tube, is fused as the tube lengtn is mechanically increased to form a wire. Very high magnetic fields with this wire have been reported at 4 K however, the performance degrades substantially above 20 to 30 K. 

The electrodeposited Bi2Sr2CaiCu2Ox (BSCCO) precursor films were obtained by co-electrodeposition of the constituent metals using nitrate salts dissolved in DMSO solvent. The electrodeposition was performed in a closed-cell configuration at room temperature ( 24°C). The cation ratios of the electrodeposition bath were adjusted systematically to obtain BSCCO precursor compositions. A typical electrolyte-bath composition for the BSCCO films consisted of 2.0-g Bi(N03)3-5H20,1.0-g Sr(N03)2, 0.6-g Ca(N03)2-4H20, and 0.9-g Cu(N03)2-6H20 dissolved in 400 mL of DMSO solvent. The substrates were single-crystal LAO coated with 300 A of Ag. 

In 1996, a 50 m underground superconducting cable (wound from 6 km of a BSCCO ribbon) and a 150 kW superconducting electric motor were successfully demonstrated. Further development of practical superconductor devices might well depend more on the development of suitable refrigeration technology than on the preparation of new superconducting materials. 

Here directions z and x correspond to the orientation of electric field across and along the layers correspondingly, Exz is the DC components of electric field, index (0 is related to the AC electric field components associated with the motion of JVL. In earlier calculations of dissipation in JFF regime [19, 24] only two first terms of Eq. (6) have been taken into account. However, as that has been pointed out recently [23], the third term can have the leading contribution for the highly anisotropic layered superconductors, satisfying the condition T = ( 1. For materials like BSCCO at low... 

Figure IV 2 10. Solid triangles show temperature dependence of the out-of-plane quasiparticle conductivity ac (a) and in-plane quasiparticle conductivity Gab (b). Below Tc they are extracted from the JFF experiment on BSCCO long stack [17] and above Tc they represent the normal state conductivities of whiskers measured independently on samples from the same batch. Open circles correspond to the oc data from Ref. 14, obtained on small mesas in zero field, open squares correspond to 14.4 GHz microwave data for cab from Ref. 18 obtained on epitaxial films. Solid lines in both plots are just guides for the eye. Insert in (a) shows the low temperature part of ac(T) plotted versus T2...

The most important result is that temperature dependence of the in-plane quasiparticle conductivity, heat transport measurements of the electronic part of the thermal conductivity [26],... 

Fig. 10b shows a comparison of our data with the microwave results [18]. The origin of the peak of oab(T) has been widely discussed as a result of a d-wave symmetry of the OP in BSCCO and YBCO. In particular, in a d-wave Fermi-liquid model it was shown that at low temperatures oab grows with temperature as [27] o(m—>0,T) = <70o (1 + fl2), where Ooo is a universal inplane conductivity introduced by Lee [28], Ooo = n e2 /(n mabAo) with mab the effective quasiparticle in-plane mass. 

Figure 2.20. Comparison of the crystal structures of Ocft-right) LSCO, YBCO, and BSCCO superconductors, respectively. Reproduced with permission from Prof. Hoffman s webpage at Harvard University http //hoffman.physics.harvard.edu/research/SCmaterials.php...

FIGURE 25.7 (a) Schematic representation of the BSCCO membrane (i) top layer of BSCCO colloids (ii) BSCCO macroporons support, (b) SEM image of the BSCCO membrane (cross-section). 

The cathodic incorporation of lithium from a solution of LiAsFg in propylene carbonate was used in the attempt [301] to obtain HTSC materials based on calcium and lanthanum niobates. The incorporation of lithium into YBCO from a similar electrolyte proceeds reversibly and ensures a discharging capacitance of the HTSC cathode high enough for application in lithium batteries [302-307]. The possibility was also reported [308-310] of incorporating lithium into BSCCO, but the capacitance values obtained are very contradictory. 

Special studies with ring-disk electrodes showed that only metals with relatively positive deposition potentials silver and mercury [53, 494] and also probably copper can be cathodically deposited on HTSC substrates without partial reduction of the oxide surface. HTSC-silver composites are fabricated by multistage techniques that include an electrodeposition stage [498, 499]. It has been noted during deposition of silver and copper that their incorporation into the BSCCO lattice is possible (0.01 and 0.4 atom per molecule, respectively) with the formation of substituted phases [495]. 

The simplest methods of HTSC analysis are based on the determination of the products of sample dissolution in acidic media. Potentiometric, amperometric, or coulometric titrations are frequently used (mainly for YBCO ceramics [525-527] and their analogs with other rare-earth elements [528, 529], and also for BSCCO [530]). We note particularly the method of potentiostatic coulometric analysis [531], which allows one to analyze thallium cuprate samples over a wide range of the Tl/Cu ratio, and also the method of flow-through coulometry for determining the effective valence of copper [532]. The polarographic determination of Cu content in the samples obtained by dissolving HTSCs in concentrated alkaline solutions with special... 

Figure 2. Parabolic dependence of of BSCCO films on oxygen surplus i5 points indicate measured data, solid line, fit using quadratic equation.

Fuflyigin VN, Kaul AR, Pozigun SA (1993) Effect of CVD process parameters on phase and chemical composition of BSCCO thin film. J Phys IV, 2, C3-361-366... 

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