Microwave absorption in the superconducting and normal phases of Y-Ba-Cu-O

Durný, R.; Hautala, J.; Ducharme, Stephen; Lee, B.; Symko, O. G.; Taylor, P. C.; Zheng, Dafang; Xu, Jin

doi:10.1103/physrevb.36.2361

Cited by 174 publications

(28 citation statements)

References 9 publications

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“…In the eutectic regions composed of two superconducting phases Mo 2 Re 3 B x and Mo 3 Re 2 B x separated by semiconducting layer of boron, there exists a Josephson junction network. Besides numerous phenomena originating from tunnelling of the Cooper pairs, the Josephson junctions characterize strong absorption of energy in microwave band [14][15][16][17]. Therefore, the Mo 2 Re 3 B x -Mo 3 Re 2 B x eutectic exhibits very large MMMA which is comparable in magnitude to the one observed in granular high-temperature superconductors.…”

Section: Microstructure Of the Eutecticsupporting

confidence: 50%

Superconducting Properties of Mo₂Re₃B_x-Mo₃Re₂B_xEutectic

et al. 2007

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We synthesized, for the first time, superconducting eutectic composed of two new superconducting phases, namely of Mo 2 Re 3 B x and of Mo 3 Re 2 B x (where x ≈ 1) and investigated its basic transport, magnetic, and microwave properties. The transition temperatures T c were equal to 6.6 K and to 8.7 K for Mo3Re2Bx and Mo2Re3Bx compound, respectively. The phases present in the eutectic were identified by means of energy dispersion spectroscopy analyses. It was also shown that the two phases in the eutectic were separated by thin boron interface and formed regular network of the Josephson junctions which very effectively absorbed microwave energy.

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Section: Microstructure Of the Eutecticsupporting

confidence: 50%

Superconducting Properties of Mo₂Re₃B_x-Mo₃Re₂B_xEutectic

et al. 2007

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“…MWA measurements are a sensitive tool for detection of the transport properties of high-T c superconductors below the critical temperature, when superconducting paths are risen and dc measurements cease to give information. Soon after the discovery of high-T c superconductivity it has been established [276][277][278][279][280], that in ceramic samples there exists a large non-resonant MWA in zero and low applied magnetic field that can be associated with the transition to the superconducting phase. In fields below H c1 the MWA of high-T c materials is due to dissipative flux motion in the link network or, equivalently, due to the junction's resistance.…”

Section: Anomalous Microwave Absorptionmentioning

confidence: 99%

Paramagnetic Meissner effect and related dynamical phenomena

2003

Physics Reports

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The hallmark of superconductivity is the diamagnetic response to external magnetic field. In striking contrast to this behavior, a paramagnetic response or paramagnetic Meissner effect was observed in ceramic high-Tc and in conventional superconductors. The present review is given on this interesting effect and related phenomena. We begin with a detailed discussion of experimental results on the paramagnetic Meissner effect in both granular and conventional superconductors. There are two main mechanisms leading to the paramagnetic response: the so called d-wave and the flux compression. In the first scenario, the Josephson critical current between two d-wave superconductors becomes negative or equivalently one has a π junction. The paramagnetic signal occurs due to the nonzero spontaneous supercurrent circulating in a loop consisting of odd number of π junctions. In addition to the d-wave mechanism we present the flux compression mechanism for the paramagnetic Meissner effect. The compression may be due to either an inhomogeneous superconducting transition or flux trap inside the giant vortex state. The flux trapping which acts like a total nonzero spontaneous magnetic moment causes the paramagnetic signal. The anisotropic pairing scenario is believed to be valid for granular materials while the flux trap one can be applied to both conventional and high-Tc superconductors. The study of different phenomena by a three-dimensional lattice model of randomly distributed π Josephson junctions with finite self-inductance occupies the main part of our review. By simulations one can show that the chiral glass phase in which chiralities are frozen in time and in space may occur in granular superconductors possessing d-wave pairing symmetry. Experimental attempts on the search for the chiral glass phase are analysed. Experiments on dynamical phenomena such as AC susceptibility, compensation effect, anomalous microwave absorption, aging effect, AC resistivity and enhancement of critical current by external electric fields are considered. These phenomena were studied by Monte Carlo and Langevin dynamics simulations which show satisfactory agreement with experiments. We present a resistively shunted junction model describing rich dynamics of Josephson junction networks.

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“…Ceramic samples were powdered into granules of 0.18 mm in diameter. The granulated sample, below Tc = 91.5 K, showed a very strong Josephson absorption related to the socalled low-field maximum of magnetically modulated microwave absorption (MMMA) [8]. This absorption made taking EPR signal impossible as its amplitude is hundred times greater than that of EPR signal.…”

Section: Methodsmentioning

confidence: 99%

Pseudorotational Averaging of EPR Spectrum of Cu(II)O₅Complex in YBa₂Cu₃O_7-δin Low Temperatures

1991

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In low temperatures the condensation of oxygen was found to occur at 05 site in an elementary cell of YBa2Cu3O7-δ being the fifth ligand forming the CuO5 complex around Cul copper in chain. This change of coordinantion from CuO4 to CuO5 is the origin of a pseudorotation related to a strong vibronic coupling of two distorted configurations: a tetragonal pyramid C4v and a trigonal bipyramid D3h, which yields a pseudocubic EPR spectrum in low temperatures. The averaged spectroscopic splitting coefficient is related to a superposition of vibronically coupled orbital states |x 2 -y2) and 3z2 -r2 ) . The averaged spectrum was for the first time observed in low temperatures since the oxygen condensation in YBa2Cu3O7-δ at 05 site of the chain occur only when oxygen undergoing fast diffusion among the chains, gets localized with decreasing temperature. The activation energy of oxygen desorption from the 05 site is 36 K.

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Microwave absorption in the superconducting and normal phases of Y-Ba-Cu-O

Abstract: Microwave absorption in the superconducting and normal phases of Y-Ba- Cu-O" (1987). Stephen Ducharme Publications. 25.

Cited by 174 publications

References 9 publications

Superconducting Properties of Mo₂Re₃B_x-Mo₃Re₂B_xEutectic

Superconducting Properties of Mo₂Re₃B_x-Mo₃Re₂B_xEutectic

Paramagnetic Meissner effect and related dynamical phenomena

Pseudorotational Averaging of EPR Spectrum of Cu(II)O₅Complex in YBa₂Cu₃O_7-δin Low Temperatures

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Microwave absorption in the superconducting and normal phases of Y-Ba-Cu-O

Abstract: Microwave absorption in the superconducting and normal phases of Y-Ba- Cu-O" (1987). Stephen Ducharme Publications. 25.

Cited by 174 publications

References 9 publications

Superconducting Properties of Mo2Re3Bx-Mo3Re2BxEutectic

Superconducting Properties of Mo2Re3Bx-Mo3Re2BxEutectic

Paramagnetic Meissner effect and related dynamical phenomena

Pseudorotational Averaging of EPR Spectrum of Cu(II)O5Complex in YBa2Cu3O7-δin Low Temperatures

Contact Info

Product

Resources

About

Superconducting Properties of Mo₂Re₃B_x-Mo₃Re₂B_xEutectic

Superconducting Properties of Mo₂Re₃B_x-Mo₃Re₂B_xEutectic

Pseudorotational Averaging of EPR Spectrum of Cu(II)O₅Complex in YBa₂Cu₃O_7-δin Low Temperatures