Effect of Mn Addition on Structural and Superconducting Properties of (Bi, Pb)-2223 Superconducting Ceramics

Yıldırım, G.; Bal, Smrutisikha; Yücel, Ersin; Doğruer, M.; Akdoğan, Mustafa; Varılcı, A.; Terzioğlu, C.

doi:10.1007/s10948-011-1324-0

Cited by 54 publications

(8 citation statements)

References 57 publications

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“…On the other hand, there are some  problems which limit the practical applications of (Bi,Pb)-2223; the most limiting parameters for the practical applications of this phase are critical current density J c and mechanical properties [2]. Since the discovery of high temperature superconductors (HTSCs), many substitutions have been carried out in BSCCO system in order to improve its T c and J c , and better understand the structural, physical, and mechanical properties [3][4][5][6][7][8]. The rare-earth element chemical substitution has an effective route in improving the flux pinning centers, which in turn enhance J c and other transport properties of (Bi,Pb)-2223 phase [9].…”

Section: Introductionmentioning

confidence: 99%

Electrical and mechanical properties of (Bi,Pb)-2223 substituted by holmium

et al. 2016

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Abstract:The effect of the partial substitution of Ca 2+ by Ho 3+ ions on the electrical and mechanical properties of the superconducting phase (Bi,Pb)-2223 was studied. Superconducting samples of the type (Bi 1.8 Pb 0.4 )Sr 2 Ca 2.1−x Ho x Cu 3.1 O 10+δ were prepared by solid-state reaction technique under ambient pressure, and characterized by means of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The superconducting transition temperature T c and pseudogap temperature T * were estimated from electrical resistivity measurements, while the critical current density J c was determined from I-V curves. The electrical resistivity data were discussed according to bipolaron model in the absence of thermally excited individual polarons. The sample with x = 0.025 showed the highest phase volume fraction, T c , and J c . Room temperature Vickers microhardness measurements were carried out at different applied loads (0.25-5 N) in order to investigate the performance of the mechanical properties of (Bi 1.8 Pb 0.4 )Sr 2 Ca 2.1−x Ho x Cu 3.1 O 10+δ phase. It was found that all the samples exhibit normal indentation size effect (ISE). The Vickers microhardness number H V increased as x increased from 0 to 0.025. The experimental results were discussed in view of Meyer's law, Hays-Kendall (HK) approach, elastic/plastic deformation (EPD) model, and proportional specimen resistance (PSR) model. The load independent (true) microhardness of (Bi 1.8 Pb 0.4 )Sr 2 Ca 2.1−x Ho x Cu 3.1 O 10+δ superconducting samples showed identical behavior to that of the PSR model.

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Section: Introductionmentioning

confidence: 99%

Electrical and mechanical properties of (Bi,Pb)-2223 substituted by holmium

et al. 2016

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“…With the increase of the Gd 3? ions in the system the normal-state resistivity enhances continuously [22,23]. Moreover, the onset critical (T onset c ) and offset critical (T offset c ) temperatures inferred from the normalized resistivity graphs are depicted in Table 1 (Table 1) as a consequence of the presence of impurities and weak links between the superconducting grains [24], being favored by the SEM investigations.…”

Section: Electrical Resistivity Measurementsmentioning

confidence: 94%

Investigation of microstructural, Vickers microhardness and superconducting properties of YBa2Cu3−xGdxO7−δ (0 ≤ x ≤ 0.150) superconducting ceramics via experimental and theoretical approaches

Doğruer

Öztürk

Varılcı

et al. 2012

J Mater Sci: Mater Electron

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This study manifests the change of pinning mechanism, electrical, structural, physical, mechanical and superconducting properties of YBa 2 Cu 3-x Gd x O 7-d superconductors samples prepared by the conventional solidstate reaction method (x = 0, 0.025, 0.050, 0.100 and 0.150) by use of dc resistivity, X-ray analysis (XRD), scanning electron microscopy (SEM) and Vickers microhardness measurements. Zero resistivity transition temperatures (T c offset ) of the samples are deduced from the dc resistivity measurements. Additionally, the lattice parameters are determined from XRD measurements when the microstructure, surface morphology and microhardness of the samples studied are examined by SEM and mechanical measurements, respectively. The results obtained demonstrate that T c offset values of the samples decrease slowly with the increase in the Gd content. The maximum T c offset (92.0 K) is obtained for the pure sample prepared at 940°C for 20 h in air atmosphere while the minimum value of 83.3 K is found for the sample doped with 0.150 Gd content. Moreover, it is obtained that J c values reduce from 132 to 34 A/cm 2 with the enhancement of the Gd level in the crystalline structure. Further, the peak intensities belonging to Y123 (major) phase are obtained to decrease whereas the peak intensities of the minor phases such as BaCuO 2 and Y211 are found to enhance systematically with the increment in the Gd content in the system, illustrating that partial substitution of Cu 2? ions by Gd 3? ions are carried out successfully. Moreover, SEM images display that the undoped sample obtains the best crystallinity and connectivity between superconducting grains and largest grain size whereas the worst surface morphology is observed for the maximum doped sample (x = 0.150). At the same time, Vickers microhardness, elastic modulus, load independent hardness, yield strength, fracture toughness and brittleness index values, playing important roles on the mechanical properties, are computed for all the samples. The experimental results of the microhardness measurements are examined using the Meyer's law, PSR (proportional specimen resistance), modified PRS, ElasticPlastic deformation model (EPD) and Hays-Kendall (HK) approach. The microhardness values obtained increase with the enhancement of the Gd content in the samples. Besides, it is noted that the Hays-Kendall approach is the most successful model explaining the mechanical properties of the samples studied in this work.

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“…Critical current density (J c ) plays an important role to explain the pinning mechanism in a material [27][28][29]. In this study, the influence of the Zr diffusion on the self field critical current density (J c ) of the Y123 superconductor ceramics is investigated and it is noted that the self field J c increases significantly with the Zr diffusion.…”

Section: Transport Critical Current Densitymentioning

confidence: 99%