Magnetization of submicron superconducting YBCO particles: isolated single vortices versus critical state model

Fleisher, V.G.; Laiho, R.; Lähderanta, E.; Stepanov, Yu. P.; Traito, K. B.

doi:10.1016/s0921-4534(96)00576-x

Cited by 8 publications

(5 citation statements)

References 23 publications

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“…The average value λ = (λ 2 ab λ c ) 1/3 agrees well with 0.14 µm quoted for sintered samples [2]. High-T c powders having particle diameter D ≤ λ show unusual behaviour with a sizedependent threshold field for magnetic flux trapping and fast relaxation [3,4]. Therefore such powders constitute an interesting subject for investigation of the basic properties of small superconducting particles.…”

Section: Introductionsupporting

confidence: 80%

Preparation of one to three unit cell thick powders and investigation of their magnetic and microwave properties

Blinov

Fleisher

Huhtinen

et al. 1997

Supercond. Sci. Technol.

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Nanocrystalline powders have been prepared by a citrate gel modification of the sol - gel technique. Using a relatively low temperature, , and (i) a process of extracting oxygen and reoxidizing the precursor powder or (ii) a sequence of vacuum annealing and prolonged heating in air, it was possible to avoid sintering of the particles. According to x-ray powder diffraction analysis the particles have orthorhombic structure pertinent to the phase. Measurements made by atomic force microscopy show that they have flat shape with two maxima in the thickness distribution, one at 1.2 nm and the other at 3.8 nm , corresponding to one or three orthorhombic unit cell lengths of the crystal. The average width of the particles is 40 nm. A similar value could be obtained from XRD measurements and the width of microwave absorption line around zero applied field. Superconducting properties of the powders were investigated with magnetization measurements.

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Section: Introductionsupporting

confidence: 80%

Preparation of one to three unit cell thick powders and investigation of their magnetic and microwave properties

Blinov

Fleisher

Huhtinen

et al. 1997

Supercond. Sci. Technol.

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“…The critical temperature T c was the same (92 K) in all the size groups. For the S and M samples the χ FC and χ Z FC curves are the same, which is expected for small particles where the threshold field for vortex penetration is high [20,21]. When measured in a field of 8 mT no difference between the ZFC and the FC curves in any of the samples was found.…”

Section: Magnetic and Microwave Properties Of The Segregated Samplessupporting

confidence: 71%

Size-dependent properties of YBa₂Cu₃O_6 xnanopowder

Paturi

Raittila

Huhtinen

et al. 2003

J. Phys.: Condens. Matter

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YBa2Cu3O6+x nanopowder, prepared by the citrate sol–gel method, is segregated by sedimentation in ethanol into three size groups with average particle heights of 0.7, 1.6 and 2.3 nm. The structural properties and composition of the powders, investigated by x-ray diffraction, atomic force microscopy, Auger electron spectroscopy and EPR-spectroscopy, show no clear differences, except the size. According to investigations by magnetometry and by non-resonant microwave absorption the as-prepared powder contains weak links which, however, disappear during the segregation. The magnetic susceptibility of the samples decreases with the decreasing particle size, in agreement with the susceptibility values calculated from the London equations for cylindrical particles smaller than the London penetration depth. In all three size groups the critical temperature of superconductivity is 92 K.

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“…We report some measured χ values, from the literature, for cuprate particles of small size: d particle 10 µm, T < 20 K, H 0 = 360 G, χ −0.8 [48]; d particle 20-50 µm, T = 80 K, H 0 = 650 G, χ −0.075 [49]; d particle 50 nm, T = 5 K, H 0 50 G, χ −0.04 − 0.09 [50] (all values in SI system and dimensionless). In polycrystalline samples of YBCO, about one third of the full Meissner effect is reported to be found for fields in the range of 100-200 G and at temperatures sufficiently below T c [51]. Demagnetization for particles [31,32] is not taken into account explicitly, this is because of the irregular (unknown) shape of crystallites produced by SSC syntheses.…”

Section: Theory Of Attractive Magnetic Capture Of Diamagnetic Particlesmentioning

confidence: 99%

Theory of high gradient attractive magnetic separation of superconducting materials and its experimental verification by YBa₂Cu₃O_xparticles

Dessauges

Willems

Favre

et al. 2006

Supercond. Sci. Technol.

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The calculation of trajectories for sedimenting diamagnetic particles shows that superconducting matter in the Meissner or vortex state can be captured sidewise to a ferromagnetic wire magnetized perpendicular to its length. Capture is possible for externally applied fields lower than typical critical fields H c1 (c), H c1 (a, b) of cuprates. For single crystalline particles in the vortex state, the magnetic anisotropy may reduce the capture force because of alignment. Theoretical predictions were confirmed experimentally for suspensions of polycrystalline and single crystalline particles of YBa 2 Cu 3 O x (size range: 2-125 µm) in liquid nitrogen. As a general conclusion we find that for the extraction of superconducting particles out of combinatorial ceramic reaction mixtures, separation in the Meissner state might be most effective because of the presence of an excess of normal state matter featuring a much lower diamagnetic susceptibility.

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Magnetization of submicron superconducting YBCO particles: isolated single vortices versus critical state model

Cited by 8 publications

References 23 publications

Preparation of one to three unit cell thick powders and investigation of their magnetic and microwave properties

Preparation of one to three unit cell thick powders and investigation of their magnetic and microwave properties

Size-dependent properties of YBa₂Cu₃O_6 xnanopowder

Theory of high gradient attractive magnetic separation of superconducting materials and its experimental verification by YBa₂Cu₃O_xparticles

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Magnetization of submicron superconducting YBCO particles: isolated single vortices versus critical state model

Cited by 8 publications

References 23 publications

Preparation of one to three unit cell thick powders and investigation of their magnetic and microwave properties

Preparation of one to three unit cell thick powders and investigation of their magnetic and microwave properties

Size-dependent properties of YBa2Cu3O6 xnanopowder

Theory of high gradient attractive magnetic separation of superconducting materials and its experimental verification by YBa2Cu3Oxparticles

Contact Info

Product

Resources

About

Size-dependent properties of YBa₂Cu₃O_6 xnanopowder

Theory of high gradient attractive magnetic separation of superconducting materials and its experimental verification by YBa₂Cu₃O_xparticles