Lower critical field, remanent magnetization and irreversibility line of ceramic (Bi,Pb)-2223-HTSC

Job, R.; Rosenberg, M.

doi:10.1016/0921-4534(91)90204-c

Cited by 37 publications

(3 citation statements)

References 15 publications

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“…However, a well-agreed conclusion with solid experimental verification on the relationship between superconductors and Lenz's law has so far been absent from the literature. To investigate this question and try to find more direct evidence able to answer it, we designed and carried out experiments based on the principle described in [3,5,17,18].…”

Section: Introductionmentioning

confidence: 99%

Superconductors and Lenz’s law

Xin¹,

Li²,

Dong³

et al. 2020

Supercond. Sci. Technol.

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A superconductor has the unique properties of zero resistance and Meissner effect. Lenz's law is a fundamental law of physics. People have occasionally brought up the question that if a superconductor abides by Lenz's law. There has been lack of an explicit answer to this question so far. Recently, we carried out experiments with superconductor coils and a magnet in search of an answer to this question. We find out that the interacting behavior between a superconducting coil and a magnet does not comply with one of the primary interpretations of Lenz's law: the current induced in a circuit due to a change or a motion in a magnetic field is so directed as to exert a mechanical force opposing the motion. Our experimental results show that the induced current in the superconducting coil do not always oppose the motion of magnet during their interaction. Instead, in a certain portion of the interaction the induced current aids the motion of the magnet. This finding may require the aforementioned interpretation of Lenz's law to be revised as superconductors are involved.

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Section: Introductionmentioning

confidence: 99%

Superconductors and Lenz’s law

Xin¹,

Li²,

Dong³

et al. 2020

Supercond. Sci. Technol.

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“…(2) and (3), we determine A, , b(T) for both neglecting and taking into consideration the correction term g ( T). These results are shown in Fig.…”

Section: And Usingmentioning

confidence: 99%

Flux-line-lattice melting inBi2Sr2
Kopelevich
¹
,
Moehlecke
²
,
Torres
³

1994
Phys. Rev. B

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We have performed dc magnetization studies in the c-axis-oriented bulk BizSrzCazCu30&0 compound.The penetration depth A, ,b( T) is extracted from reversible magnetization data M (H) taking into account fluctuations of the vortices. An "irreversibility line" is quantitatively compared with predictions of flux-line-lattice (FLL) melting models. The results strongly suggest that the "irreversibility line" near T, is associated with melting of FLL caused by thermal fluctuations.It is now widely accepted that thermal fluctuations play an important role in the thermodynamic and transport properties of high-temperature supereonductors. The large fluctuations are caused by the high transition temperature T" the short coherence length g, and strong anisotropy of these materials. The fluctuations are responsible for the "anomalous" behavior of reversible magnetization M(H, T). 'Here the magnetization becomes independent of field at some temperature T', which is several degrees below the mean-field transition temperature T,o, i.e. , all M(T} curves for difFerent H cross at the temperature T'. The experimental results have been well described in the model of a threedimensional (3D) XY critical point and in terms of the Ginsburg-Landau fluctuation theory, using the lowest Landau-level approximation.Bulaevskii, Ledvij, and Kogan have shown that in the London regime where the magnetization logarithmically changes with field, the existence of the crossing temperature T* is a result of thermal fluctuations of vortices. They also argue that the superconducting transition temperature Tsc in layered superconductors is the analog of the KosterlitzThouless vortex-antivortex dissociation temperature which lies below T,o. Thus, the resistivity approaches zero at Tsc. For T & Tsc, the motion of dissociated vortex -antivortex pairs give rise to dissipation. Further Kogan et al. ' have demonstrated from magnetization measurements in BizSrzCaCuz08 that vortex fluctuations have a strong influence on the London penetration depth A, (T). On the other hand, strong fiuctuations can lead to melting of the flux-line lattice. " ' In the hightemperature region where the London penetration depth A, ( T)~(1 -T/T, ) '~~, 3D FLL melting models predict a power law for the "melting line" (ML) of the form H~(1 -T/T, ), with a=2. " ' In Josephson-coupled layered superconductor s like Bi-and Tl-based compounds, the thermal vortex fluctuations are enhanced due to weak coupling between CuOz superconducting planes. At the same time, for these strongly anisotropic superconductors, "irreversibility lines" (IL's) near T, have been shown to fit the power-law relationship H;~(1 -T/T, ) with a substantially smaller than 2 (e.g. , Refs. 20 and 21 reported values of an exponent a close to 1), where the T, used is the measured superconducting transition temperature. These results imply that IL in 4o, nH. z 32m A, , b(T) eH k~T 16+k~Tl n ppd apodH v'e the vicinity of T, is not a 3D ML (here we discuss dc IL s which are suitable for comparison with predictions of melting ...

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“…The sample of the ceramic bismuth-based 2223 superconductor, partially substituted with Pb for Bi atoms, was prepared by the standard solid state reaction procedure that was well described in the literature [1]. The X-ray diraction showed that there are two superconducting phases: the dominant 2223 phase with T c,50% = 107.1 K and the minor 2212 phase with T c = 90 K. The measurements of the resistance versus temperature and magnetic eld were carried out using the four probes a.c. method.…”

Section: Methodsmentioning

confidence: 99%

Study of Resistive Superconducting Transition of Bulk (Bi_{0.6}Pb_{0.4})_2Sr_2Ca_2Cu_{3}O_{x}

et al. 2014

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The temperature widths of the resistive transition as well as the thermal uctuations of bulk (Bi0.6Pb0.4)2Sr2Ca2Cu3Ox superconductor with T c,50% = 107.1 K were studied. The applied magnetic eld widens the resistive transition according to the following formula: ∆T = CH m + ∆T0. The value of exponent m = 0.44 suggests that there is strong pining of vortices, especially at lower temperatures. The critical exponents λ of the conductivity were calculated using the following equation: ∆σ = Kε −λ , with the λ1 = 1.75 close to the zero critical temperature and λ2 = 3.77 at higher temperatures. These values were discussed within the available theoretical models.

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Lower critical field, remanent magnetization and irreversibility line of ceramic (Bi,Pb)-2223-HTSC

Cited by 37 publications

References 15 publications

Superconductors and Lenz’s law

Superconductors and Lenz’s law

Flux-line-lattice melting inBi2Sr2
Kopelevich
¹
,
Moehlecke
²
,
Torres
³

1994
Phys. Rev. B

Study of Resistive Superconducting Transition of Bulk (Bi_{0.6}Pb_{0.4})_2Sr_2Ca_2Cu_{3}O_{x}

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Lower critical field, remanent magnetization and irreversibility line of ceramic (Bi,Pb)-2223-HTSC

Cited by 37 publications

References 15 publications

Superconductors and Lenz’s law

Superconductors and Lenz’s law

Flux-line-lattice melting inBi2Sr2Kopelevich1, Moehlecke2, Torres3 1994Phys. Rev. B

Study of Resistive Superconducting Transition of Bulk (Bi_{0.6}Pb_{0.4})_2Sr_2Ca_2Cu_{3}O_{x}

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About

Flux-line-lattice melting inBi2Sr2
Kopelevich
¹
,
Moehlecke
²
,
Torres
³

1994
Phys. Rev. B