Critical current densities of Bi-2212 thick films processed from commercial precursors

Sager, D.; Gauckler, Ludwig J.; Chen, M.

doi:10.1016/j.physc.2004.12.016

Cited by 7 publications

(4 citation statements)

References 14 publications

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“…However, when the addition of Al 2 O 3 exceeds [13,27]. Here we note the importance of the characteristic of the starting powders [28] and the compacting pressure [27] which play an important role in determining the superconducting phase microstructure in polycrystalline (Bi,Pb)-2223 and also the electrical transport properties. Fig.…”

Section: Superconductivitymentioning

confidence: 74%

Flux pinning by Al-based nano particles embedded in polycrystalline (Bi,Pb)-2223 superconductors

Ghattas¹,

Annabi²,

Zouaoui³

et al. 2008

Physica C: Superconductivity and its Applications

107

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Section: Superconductivitymentioning

confidence: 74%

Flux pinning by Al-based nano particles embedded in polycrystalline (Bi,Pb)-2223 superconductors

Ghattas¹,

Annabi²,

Zouaoui³

et al. 2008

Physica C: Superconductivity and its Applications

107

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“…Typical methods are spray pyrolysis [24,25], co-precipitation [26,27] and solgel [28]. Among these, spray pyrolysis [29] is the most promising because it allows precise control the of stoichiometry and produces homogeneous Bi2212 powders.…”

Section: Introductionmentioning

confidence: 99%

“…These studies propose requirements on stoichiometry, phase purity, homogeneity and carbon content of Bi2212 precursors in the green wire. Yet, far fewer studies have discussed the effect of precursor stoichiometry on wire performance [23,36], and most of those either focused solely on the synthesis process and properties of Bi2212 bulk materials [24,[37][38][39][40][41][42] or studied precursor properties by comparing superconducting tapes/ thick films that had varying methods, geometries and substrates [10,19,29,43,44]. Furthermore, recent over-pressure (OP) processing has effectively reduced gross microstructural porosity in Bi2212 wire, resulting in greatly increased critical current density ( J c ) [45].…”

Section: Introductionmentioning

confidence: 99%

High critical current density Bi₂Sr₂CaCu₂O_x/Ag wire containing oxide precursor synthesized from nano-oxides

Zhang

Johnson

Naderi

et al. 2016

Supercond. Sci. Technol.

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Bi2Sr2CaCu2Ox (Bi2212)/Ag-alloy wires are manufactured via the oxide-powder-in-tube route by filling Ag/Ag-alloy tubes with Bi2212 oxide precursor, deforming into wire, restacking and heat treating using partial-melt processing (PMP). Recent studies propose several requirements on precursor properties, including stoichiometry, chemical homogeneity, carbon content and phase purity. Here, nanosize oxides produced by nGimat’s proprietary NanoSpray CombustionTM process are used as starting materials to synthesize Bi2212 oxide precursors via solid-state calcination. Oxide powders for wire fill (precursor powder) with precisely controlled stoichiometry and chemical homogeneity containing over 99 vol% of single Bi2212-phase are synthesized. Alkaline-earth cuprate are found to be the only impurity phase in the precursor powders. Phase transformation, carbon release and grain growth during calcination are studied through a series of quench studies. Effects of particle size, surface area, stoichiometry, chemical homogeneity and microstructures of the starting materials on Bi2212 formation and wire transport properties are discussed. Small particle size, high surface area and short diffusion length of the starting materials result in a rapid and homogeneous phase transformation to Bi2212, along with an early and rapid carbon release. The residual carbon in the precursor powder is between 50 and 90 ppm. The strong dependence of transport Jc on precursor stoichiometry indicates that compositional variations within precursor powders should be less than 1.5 mol%. Two Bi-rich and Ca-deficient stoichiometries give higher wire transport critical current density, with the highest being 2520 A mm−2 (4.2 K, 5 T) after 1 bar PMP and 4560 A mm−2 (4.2 K, 5 T) after 100 bar overpressure (OP) processing. The low residual carbon content results in smaller and fewer voids within an OP-processed wire filament. Bi-rich and Ca-deficient stoichiometries and small compositional variations within precursor powders may be a method for engineering uniformly-distributed and high-density Bi2201 intergrowths within Bi2212 grains after PMP.

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“…Aiming at the practical applications, many investigations focused on the studies of Bi-2212 tapes (wires) [11][12][13][14] and thick films [15][16][17]. Elementary doping was proved to be an effective way for the optimization of superconducting properties by tuning the lattice structure, microstructure, thermodynamic behaviors, and electrical/magnetical properties of Bi-2212.…”

Section: Introductionmentioning

confidence: 99%

Doping effects on Bi-2212 high temperature superconducting thick films

Zhang

Hao

et al. 2015

J Mater Sci: Mater Electron

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Superconducting thick films of Bi 2 Sr 2 Ca 0.95 M 0.05 Cu 2.0 O 8?d (Bi-2212) with M = K, Li, and Al were fabricated by a dip coating process. The influences of different doping elements on the lattice structure, electrical transport properties and related superconducting properties were systematically investigated. XRD analyses confirmed that all the doping ions have successfully entered into the Bi-2212 matrix, and led to a systematical change of lattice parameters. Due to the change of thermodynamic properties with doping, the phase evolution process changed during the sintering process. Thus both the content of secondary phases and the size of Bi-2212 crystals changed, which influenced the intergrain connections. The carrier concentrations of thick films were also influenced by doping, which contributed to the changes of critical temperature. It can be deduced that the hole doping with either K ? or Li ? can tune the samples into overdoping region, thus led to the increase of critical current at 77 K with the maximum critical current density of *5300 A/cm 2 .

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Critical current densities of Bi-2212 thick films processed from commercial precursors

Cited by 7 publications

References 14 publications

Flux pinning by Al-based nano particles embedded in polycrystalline (Bi,Pb)-2223 superconductors

Flux pinning by Al-based nano particles embedded in polycrystalline (Bi,Pb)-2223 superconductors

High critical current density Bi₂Sr₂CaCu₂O_x/Ag wire containing oxide precursor synthesized from nano-oxides

Doping effects on Bi-2212 high temperature superconducting thick films

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Critical current densities of Bi-2212 thick films processed from commercial precursors

Cited by 7 publications

References 14 publications

Flux pinning by Al-based nano particles embedded in polycrystalline (Bi,Pb)-2223 superconductors

Flux pinning by Al-based nano particles embedded in polycrystalline (Bi,Pb)-2223 superconductors

High critical current density Bi2Sr2CaCu2Ox/Ag wire containing oxide precursor synthesized from nano-oxides

Doping effects on Bi-2212 high temperature superconducting thick films

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Product

Resources

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High critical current density Bi₂Sr₂CaCu₂O_x/Ag wire containing oxide precursor synthesized from nano-oxides