Inversion of Meissner effect and granular disorder in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} superconductors

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.6625· OSTI ID:505615

Khalil, A E ^[1]

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1. Physics Department, University of Bahrain, P.O. Box 32038 (Bahrain)

An explanation for the paramagnetic Meissner effect, which was recently observed in Bi high-temperature superconductors, based on the nature of the granular disorder of the material is developed. This explanation takes into account the appearance of a first-order phase transition (superconductor to superconductor) around randomly distributed defects with localized superconducting states of different orbital momenta (LS{sub n}{r_arrow}LS{sub n+1}), where n is the angular momentum of the state. The transition between superconducting states below the critical temperature in the disordered system is accompanied by jumps of the magnetic moments. When the disordered nature of the defects is taken into account, a state with an average moment greater than zero in a certain domain of the phase space will be formed and the susceptibility M/H in this case will tend toward a finite positive value as H{r_arrow}0. A comparison between the experimental measurements of a Bi-2212 ceramic sample and the theoretical predictions of the model shows that they are in good agreement. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 505615
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 10 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH OXIDES
CALCIUM OXIDES
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
MAGNETIC FLUX
MAGNETIC SUSCEPTIBILITY
MEISSNER-OCHSENFELD EFFECT
PHASE SPACE
STRONTIUM OXIDES
TRANSITION TEMPERATURE