Inter- and intragrain effects in superconducting ceramics studied by Modulated Microwave Absorption

Czyżak, B.

doi:10.1007/bf03162597

Cited by 4 publications

(2 citation statements)

References 28 publications

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“…The other widely observed feature in the field-dependent microwave absorption is the hysteretic behaviour [8][9][10][11]. It has been attributed to a consequence of reversible and irreversible processes associated with a superconducting critical state with pinning and depinning of fluxons during a modulation cycle [11].…”

Section: Introductionmentioning

confidence: 99%

Particle size dependence of zero-field microwave absorption in powdered Bi - Sr - Ca - Cu - O superconductors

Topacli

Harris

1997

J. Phys.: Condens. Matter

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The non-resonant magnetically modulated microwave response measurements of powdered Bi - Sr - Ca - Cu - O samples using the conventional EPR spectrometer are presented. After cooling in a near zero magnetic field, all samples exhibited a sharp (about ) microwave absorption with applied magnetic field, superimposed on the widely observed and well explained broader minimum. The width of the absorption maximum is found to be dependent on the particle size. It becomes broader with decreasing particle size. The effects of particle size and field history on the peak are given in detail and some possible mechanisms to account for the observations are presented.

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Section: Introductionmentioning

confidence: 99%

Particle size dependence of zero-field microwave absorption in powdered Bi - Sr - Ca - Cu - O superconductors

Topacli

Harris

1997

J. Phys.: Condens. Matter

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“…Measurements of microwave absorption have been applied in the study of inter-and intragrain flux pinning [9], 2D phenomena [10] and the Josephson critical field [11]. The magnetically modulated microwave absorption (MMMA) signal can be treated as a monitor of magnetic flux penetrating the sample [12].…”

Section: Introductionmentioning

confidence: 99%

Variation of the microstructure and flux penetration in solid solutions prepared by melt processing

Plesch

Hanic

Buchta

et al. 1996

Supercond. Sci. Technol.

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The substitution of Sr 2+ for Ba 2+ in YBa 2−x Sr x Cu 3 O y solid solutions (0 ≤ x ≤ 1) leads to a systematic decrease of the unit cell volume with increasing x value due to the smaller ionic radius of Sr 2+ replacing Ba 2+ in the structure. The growing strain, which is introduced into the structure by this substitution, distinctly influences the equilibrium in the process of crystal growth. This leads to a strong decrease of the texture and porosity of YBa 2−x Sr x Cu 3 O y samples prepared by melting techniques, when the Sr concentration increases. The additional non-superconducting phases, which are formed in the process of the partial decomposition of the solid solution above the peritectic temperature, are characterized by optical microscopy in polarized light and electron microanalysis. Measurements of the magnetically modulated microwave absorption (MMMA) in YBa 2−x Sr x Cu 3 O y (x = 0.4, 0.6, 0.8) solid solutions with different porosity and grain sizes prepared by the quench and melt technique allow one to analyse the interand intragrain flux penetration. The MMMA hysteresis width strongly depends on the sweep range of external magnetic field. The signal is reversible for the lowest sweep range, when the surface supercurrents allow Meissner shielding. When the sweep range increases, magnetic field begins to penetrate the sample through the intergrain weak links and irreversibility of the MMMA signal appears as a consequence of intergrain pinning of Josephson vortices. On further increase of the magnetic field sweep range, MMMA hysteresis width reflects the intragrain penetration. In contrast to porous samples, where all these stages can be clearly resolved, in solid solutions with low porosity flux pinning is enhanced and the role of intergrain Josephson coupling is significantly reduced.

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Properties of YBa2Cu3O7—δ–Pb(Sc0.5Ta0.5O3 Superconducting Composites

Czyżak

Andrzejewski

Hilczer

et al. 1997

phys. stat. sol. (a)

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A microbore flow injection analysis–immobilized enzyme reactor–electrochemical detection (FIA‐IMER‐ECD) system for glucose and lactate detection was built up. The assays were precise, sensitive and practicable for determination of glucose and lactate levels in hypothalamic dialysate. The method had been used to detect the dynamic changes of glucose and lactate levels during rat exhausting swimming and recovery. The data showed that after exhausting swimming, the concentration of glucose in hypothalamic dialysate that reflected the concentration in the hypothalamic extracellular fluid decreased. The level fell to its nadir at day 1 after the exercise and then went back to the basal level at day 3 after the swimming. However, lactate levels increased to a maximum at day 3 and went back to the basal level at day 5 after the swimming. Copyright © 2002 John Wiley & Sons, Ltd.

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Inter- and intragrain effects in superconducting ceramics studied by Modulated Microwave Absorption

Cited by 4 publications

References 28 publications

Particle size dependence of zero-field microwave absorption in powdered Bi - Sr - Ca - Cu - O superconductors

Particle size dependence of zero-field microwave absorption in powdered Bi - Sr - Ca - Cu - O superconductors

Variation of the microstructure and flux penetration in solid solutions prepared by melt processing

Properties of YBa2Cu3O7—δ–Pb(Sc0.5Ta0.5O3 Superconducting Composites

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