Strong magnetic field dependence of the critical currents correlated to the microstructure of YBaCuO ceramics

Dai, Uri; Deutscher, G.; Lacour, Claude; Laher-Lacour, F.; Mocaer, P.; Laguës, M.

doi:10.1063/1.102537

Cited by 16 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…͑1͒ For a sample cooled in zero field ͑ZFC͒, as the field is initially increased from zero the grains are in the Meissner state and exclude flux completely causing excess flux to be compressed into the intergranular spaces. 2,26,27 The fluxdensity distribution within the grain is uniformly zero everywhere as shown in Fig. 2͑a͒.…”

Section: Theoretical Modelmentioning

confidence: 96%

Hysteretic internal fields and critical currents in polycrystalline superconductors

Kunchur

Askew

1998

Journal of Applied Physics

View full text Add to dashboard Cite

The transport critical current J c in a polycrystalline superconductor is a hysteretic function of applied magnetic field H 0 due to flux trapping by grains. This effect has been observed by several groups and attempts have been made to calculate the intergranular field H i as a function of the applied H 0 in terms of an effective geometrical demagnetization factor D. In general a first-principles calculation of D is very difficult, and furthermore, D is not constant but is itself a hysteretic function of H 0. We develop a self-consistent scheme to extract the D and H i directly from the J c (H 0) data itself. Our model exploits the fact that there are two field ranges for which the demagnetizing field is a simple function of H 0. At low virgin fields, in the Meissner state, the susceptibility v ϷϪ1/4 is well defined, leading to a multiplicative correction: H i ϭH 0 /(1 ϩD4 v). For fields that have returned from high values, a complete critical state is established and M is well defined-although v is unknown. This leads to an additive correction: H i ϭH 0 ϪD4M for the total field. By matching J c data in increasing and decreasing fields that satisfy these special cases, it is possible to extract the relevant parameters of the problem without detailed knowledge of the demagnetization geometry. We use this model to analyze data measured on sintered YBa 2 Cu 3 O 7 superconductive rods.

show abstract

Section: Theoretical Modelmentioning

confidence: 96%

Hysteretic internal fields and critical currents in polycrystalline superconductors

Kunchur

Askew

1998

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…A hysteretic behaviour of J, has also been reported in I-V measurements [5,6,7,8] when increasing and decreasing an applied magnetic field. A tentative explanation has been given in terms of the local field dependence of J, in the intergrain regions [9,10,11].…”

Section: Introductionmentioning

confidence: 53%

Anomalous increase of the transport and inductive critical current density due to low DC-field cooling in sintered RBa₂Cu₃O_7-xhigh T_csuperconductors

Puig¹,

Pont²,

Muñoz³

1992

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

Electrical Properties Correlated to the Chemical and Granular Microstructures in YBaCuO Ceramics

Lacour

Laher-Lacour

Dubon

et al. 1991

Phys. Stat. Sol. (a)

View full text Add to dashboard Cite

Two types of correlations between the superconducting properties and the microstructures in YBaCuO ceramics prepared by the freeze‐drying method are studied. The first one is a correlation between the critical current density Jc in zero magnetic field, the diamagnetic effect, and the anisotropy of the crystal growth. It is observed that the more the crystal growth is isotropic, the larger is the critical current at 77 K. The second one is a correlation between Jc and the chemical microstructure supported by numerous X‐ray microanalyses which show that Jc is statistically strongly dependent on the couple concentration—distribution of the CuO residual phase.

show abstract

Strong magnetic field dependence of the critical currents correlated to the microstructure of YBaCuO ceramics

Cited by 16 publications

References 11 publications

Hysteretic internal fields and critical currents in polycrystalline superconductors

Hysteretic internal fields and critical currents in polycrystalline superconductors

Anomalous increase of the transport and inductive critical current density due to low DC-field cooling in sintered RBa₂Cu₃O_7-xhigh T_csuperconductors

Electrical Properties Correlated to the Chemical and Granular Microstructures in YBaCuO Ceramics

Contact Info

Product

Resources

About

Strong magnetic field dependence of the critical currents correlated to the microstructure of YBaCuO ceramics

Cited by 16 publications

References 11 publications

Hysteretic internal fields and critical currents in polycrystalline superconductors

Hysteretic internal fields and critical currents in polycrystalline superconductors

Anomalous increase of the transport and inductive critical current density due to low DC-field cooling in sintered RBa2Cu3O7-xhigh Tcsuperconductors

Electrical Properties Correlated to the Chemical and Granular Microstructures in YBaCuO Ceramics

Contact Info

Product

Resources

About

Anomalous increase of the transport and inductive critical current density due to low DC-field cooling in sintered RBa₂Cu₃O_7-xhigh T_csuperconductors