Misalignment angles and the 2D–3D temperature crossover in Bi2212 multifilaments studied using transport critical current densities

Bourgault, D.; Flahaut, Emmanuel; Antonevici, A.; Bruzek, Christian-Éric; Lallouet, N.; Soubeyroux, J.L.; Tournier, R.

doi:10.1088/0953-2048/17/3/027

Cited by 7 publications

(7 citation statements)

References 22 publications

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“…After PMP, uniaxially c-axis textured Bi2212 grains are observed within individual filaments, as compared to the circular texture found in OPIT Bi2212 after PMP [72]. The basal-plane from a cross-sectional view of the wire nearly extends the entire filament width.…”

Section: Conversion and Pmp Stagesmentioning

confidence: 81%

Formation of Bi₂Sr₂CaCu₂O_x/Ag multifilamentary metallic precursor powder-in-tube wires

Zhang

Koch

Schwartz

2016

Supercond. Sci. Technol.

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Previously, a metallic precursor (MP) approach to synthesizing Bi2Sr2CaCu2Ox (Bi2212), with a homogeneous mixture of Bi, Sr, Ca, Cu and Ag was produced by mechanical alloying. Here, Bi2212/Ag round multifilamentary wire is manufactured using a metallic precursor powder-in-tube (MPIT) process. The MP powders were packed into a pure Ag tube in an Ar atmosphere and then sealed. After deformation, multifilamentary round wires and rolled tapes were heat treated in flowing oxygen through three stages: oxidation, conversion and partial-melt processing (PMP). Processing-microstructure-property relationships on 20–50 mm long multifilamentary round wires and rolled tapes were studied extensively. It is shown that conventional wire deformation processes, optimized for oxide-powder-in-tube wires, are not effective for deforming MPIT wires, and that as with prior studies of MPIT Bi2Sr2Ca2Cu3Oy conductors, hot extrusion is required for obtaining a multifilamentary structure with fine filaments. As a result, the Bi2212 MPIT wires reported here have low engineering critical current density. Nonetheless, by focusing on sections of wires that remain intact after deformation, it is also shown that the first heat treatment stage, the oxidation stage, plays a crucial role in chemical homogeneity, phase transformation, and microstructural evolution and three reaction pathways for MP oxidation are presented. Furthermore, it is found the Bi2212 grain alignment within an MPIT filament is significantly different from that found in OPIT filaments after PMP, indicating the formation of highly dense filaments containing Bi2212 fine grains and Ag particles before PMP aids the formation of large, c-axis textured Bi2212 filaments during PMP. These results show that, with improved wire deformation, high critical current density may be obtained via a MPIT process.

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Section: Conversion and Pmp Stagesmentioning

confidence: 81%

Formation of Bi₂Sr₂CaCu₂O_x/Ag multifilamentary metallic precursor powder-in-tube wires

Zhang

Koch

Schwartz

2016

Supercond. Sci. Technol.

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“…With the application of magnetic field during split melt processing, however, the field angle dependence on I c is increased, especially for the wire with the magnetic field applied during both heat treatments (process B) as compared to those without magnetic field. Figure 5 shows the average misalignment angle, ϕ avg , of samples treated with and without magnetic field as calculated using (1) and following the approach detailed in [30,43]:…”

Section: Experimental Approachmentioning

confidence: 99%

On the influence of magnetic field processing on the texture, phase assemblage and properties of low aspect ratio Bi₂Sr₂CaCu₂O_x/AgMg wire

Liu

Schwartz

2009

Science and Technology of Advanced Materials

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Bi 2 Sr 2 CaCu 2 O x /AgMg conductors are potentially important for many applications up to 20 K, including magnets for cryogen-free magnetic resonance imaging and high field nuclear magnetic resonance research. One promising approach to increased critical current density is partial-melt processing in the presence of a magnetic field which has been shown to enhance c-axis texturing of wide, thin tape conductors. Here, we report on low aspect ratio rectangular conductors processed in an 8 T magnetic field. The magnetic field is applied during different stages of the heat treatment process. The conductors are electrically characterized using four-point critical current measurements as a function of magnetic field and magnetic field orientation relative to the conductor. The superconductive transition and magnetization hysteresis are measured using a SQUID magnetometer. The microstructures are characterized using scanning electron microscopy and energy dispersive spectroscopy and analyzed using digital image processing. It is found that the presence of a magnetic field during split melt processing enhances the electrical transport and magnetic behavior, but that the anisotropy is not consistently affected. The magnetic field also affects development of interfilamentary Bi2212 bridges, and that this depends on the initial shape of the Bi2212 filament. At least two behaviors are identified; one impacts the oxide phase assemblage and the other impacts textured growth.

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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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Misalignment angles and the 2D–3D temperature crossover in Bi2212 multifilaments studied using transport critical current densities

Cited by 7 publications

References 22 publications

Formation of Bi₂Sr₂CaCu₂O_x/Ag multifilamentary metallic precursor powder-in-tube wires

Formation of Bi₂Sr₂CaCu₂O_x/Ag multifilamentary metallic precursor powder-in-tube wires

On the influence of magnetic field processing on the texture, phase assemblage and properties of low aspect ratio Bi₂Sr₂CaCu₂O_x/AgMg wire

Doping effects on Bi-2212 high temperature superconducting thick films

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Misalignment angles and the 2D–3D temperature crossover in Bi2212 multifilaments studied using transport critical current densities

Cited by 7 publications

References 22 publications

Formation of Bi2Sr2CaCu2Ox/Ag multifilamentary metallic precursor powder-in-tube wires

Formation of Bi2Sr2CaCu2Ox/Ag multifilamentary metallic precursor powder-in-tube wires

On the influence of magnetic field processing on the texture, phase assemblage and properties of low aspect ratio Bi2Sr2CaCu2Ox/AgMg wire

Doping effects on Bi-2212 high temperature superconducting thick films

Contact Info

Product

Resources

About

Formation of Bi₂Sr₂CaCu₂O_x/Ag multifilamentary metallic precursor powder-in-tube wires

Formation of Bi₂Sr₂CaCu₂O_x/Ag multifilamentary metallic precursor powder-in-tube wires

On the influence of magnetic field processing on the texture, phase assemblage and properties of low aspect ratio Bi₂Sr₂CaCu₂O_x/AgMg wire