Argon Annealing and Oxygen Purity Affect Structural and Critical Parameters of YBCO Copper Oxide System

Ali, Atif Mossad; Sedky, A.; Algarni, H.; Sayed, M. A.

doi:10.1007/s10909-019-02234-2

Cited by 5 publications

(2 citation statements)

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“…Table 3 lists some of these examples. The obtained J c (0) value for YBCO foam is obviously higher than that of YBCO system prepared by argon annealing [54]. This may be attributed to the fact that a loss of oxygen (oxygen deficiency) and a local rearrangement of oxygen vacancies either in the chains or in planes have occurred within the Ar-annealed samples, which destroyed the pairing conductions.…”

Section: Discussionmentioning

confidence: 84%

Excess Conductivity Analysis of an YBCO Foam Strut and Its Microstructure

Slimani,

Hannachi,

Koblischka-Veneva

et al. 2024

Preprint

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Struts of a superconducting YBa2Cu3Oy (YBCO) foam prepared by the infiltration growth method on the base of commercial polyurethane foams were extracted from the bulk, and thoroughly characterized concerning the microstructure and the magnetoresistance, measured by the four-point technique. Optical microscopy, electron microscopy, electron backscatter diffraction and atomic force microscopy observations indicate an unique microstructure of the foam struts which shows a large amount of tiny Y2BaCuO5 (Y-211) particles (with diameters between 50–100 nm) being enclosed in channel-like grain boundaries between the YBCO grains and an one-of-a-kind surface of the struts covered with Ba3Cu5Oy-particles. The resistance data obtained at temperatures in the range 4.2 K ≤T≤ 150 K (applied magnetic fields ranging from 0 to 7 T) were analyzed in the framework of the fluctuation-induced conductivity (FIC) approach using the Aslamazov-Larkin model. The resulting FIC curves reveal the presence of five distinct fluctuation regimes, namely, the short-wave (SWF), one-dimensional (1D), two-dimensional (2D), three-dimensional (3D), and critical (CR) fluctuation domains. The analysis of the FIC data enable the coherence length in the direction of the c-axis at zero-temperature (ξc(0)), the lower and upper critical magnetic fields (Bc1, Bc2), the critical current density at T= 0 K (Jc(0)) and several other parameters describing the the material’s superconducting properties to be determined. The present data reveal that the minuscule Y-211 particles found along the YBCO grain boundaries alter the excess conductivity and the fluctuation behavior as compared to conventional YBCO samples, leading to a quite high value for Jc(0) for a sample without added flux pinning centers.

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Section: Discussionmentioning

confidence: 84%

Excess Conductivity Analysis of an YBCO Foam Strut and Its Microstructure

Slimani,

Hannachi,

Koblischka-Veneva

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…Table 3 lists some of these examples. The obtained J c (0) value for YBCO foam is obviously higher than that of the YBCO system prepared by argon annealing [56]. This may be attributed to the fact that a loss of oxygen (oxygen deficiency) and a local rearrangement of oxygen vacancies either in the chains or in planes have occurred within the Ar-annealed samples, which destroyed the pairing conductions.…”

mentioning

confidence: 83%

Excess Conductivity Analysis of an YBCO Foam Strut and Its Microstructure

Slimani,

Hannachi,

Koblischka-Veneva

et al. 2024

Materials

View full text Add to dashboard Cite

Struts of a superconducting YBa2Cu3Oy (YBCO) foam prepared by the infiltration growth method on the base of commercial polyurethane foams were extracted from the bulk, and thoroughly characterized concerning the microstructure and the magnetoresistance, measured by the four-point technique. Optical microscopy, electron microscopy, electron backscatter diffraction and atomic force microscopy observations indicate a unique microstructure of the foam struts which shows a large amount of tiny Y2BaCuO5 (Y-211) particles (with diameters between 50 and 100 nm) being enclosed in channel-like grain boundaries between the YBCO grains and a one-of-a-kind surface of the struts covered with Ba3Cu5Oy-particles. The resistance data obtained at temperatures in the range 4.2 K ≤T≤ 150 K (applied magnetic fields ranging from 0 to 7 T) were analyzed in the framework of the fluctuation-induced conductivity (FIC) approach using the models of Aslamazov–Larkin (AL) and Lawrence–Doniach (LD). The resulting FIC curves reveal the presence of five distinct fluctuation regimes, namely, the short-wave (SWF), one-dimensional (1D), two-dimensional (2D), three-dimensional (3D), and critical (CR) fluctuation domains. The analysis of the FIC data enable the coherence length in the direction of the c-axis at zero-temperature (ξc(0)), the irreversibility field (Birr), the upper critical magnetic field (Bc2), the critical current density at T= 0 K (Jc(0)) and several other parameters describing the the material’s superconducting properties to be determined. The present data reveal that the minuscule Y-211 particles found along the YBCO grain boundaries alter the excess conductivity and the fluctuation behavior as compared to conventional YBCO samples, leading to a quite high value for Jc(0) for a sample with a non-optimized pinning landscape.

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