Flux pinning properties of Yb substituted (Bi,Pb)-2212 superconductor

This study reports the effect of Cr addition on the structural and superconducting properties of Bi 1.8 Sr 2.0 Crx Ca 1.1 Cu 2.1 O y superconductor with x = 0, 0.1, 0.3, 0.5 0.7, and 1 by means of X-ray analysis (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and resistivity measurements. The samples studied in this work were prepared using the standard solid-state reaction method. Zero resistivity transition temperatures (T c ) are qualitatively estimated from the dc resistivity measurements. The zero resistivity transition temperatures are obtained to decrease from 81 K to 53 K with the increase in Cr addition. Moreover, the phase and lattice parameters were determined from XRD measurements. Based on the refinement of cell parameters done by considering the structural modulation, the Cr addition was confirmed by an increase of the lattice parameter a and decrease of the cell parameter a of the samples in comparison with that of the undoped sample (Cr0). As for the microstructure and element composition analyses on the surface of the samples produced, SEM and EDS measurements were investigated. According to the measurements, not only were the grain sizes of the samples noted to decrease, but also the surface morphology and grain connectivity were obtained to degrade with increase in the

Section: Xrd Analysesmentioning

confidence: 84%

Investigation of Structural and Superconducting Properties of Cr Added Bi-2212 Superconducting Ceramics

Yıldırım

Yücel

Bal

et al. 2011

“…One can see from the table, the percentage of (Bi, Pb)-2223 phase decreases and that of (Bi, Pb)-2212 phase increases with the Mn addition. Additionally, a systematic expansion in the a-axis length is observed [38][39][40][41] while a regular contraction in the c-axis length is obtained with the increase [42][43][44][45] in the Mn addition. It is well known that the lattice parameter a is controlled by the length of in-plane Cu-O bond [46].…”

Section: Xrd Analysesmentioning

confidence: 80%

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

Yıldırım

Bal

Yücel

et al. 2011

This study deals with the effect of Mn addition on the structural and superconducting properties of Bi 1.8 Pb 0.4 Sr 2 Mn x Ca 2.2 Cu 3.0 O y ceramics with x = 0, 0.03, 0.06, 0.15, 0.3 and 0.6 by means of X-ray analysis (XRD), scanning electron microscopy (SEM), electron dispersive X-ray (EDX), resistivity, and transport critical current density (J c ) measurements. Zero-resistivity transition temperatures (T c ) of the samples produced via the standard solidstate reaction method are estimated from the dc resistivity measurements. Moreover, the phase fraction and lattice parameters are determined from XRD measurements while the microstructure, surface morphology and element composition analyses of the samples are investigated by SEM and EDX measurements, respectively. It is found that T c values are obtained to decrease from 109 K to 85 K; likewise, J c values are observed to reduce from 3200 A/cm 2 to 125 A/cm 2 with increasing Mn addition. According to the refinement of cell parameters done by considering the structural modulation, the Mn addition is confirmed by both an increase of the lattice parameter a and a decrease of the cell parameter c of the samples in comparison with that of the pure sample (Mn0). SEM measurements show that not only the surface morphology and grain connectivity are seen to degrade but the grain sizes of the samples are found to decrease with the increase of the Mn addition as well. The EDX results reveal that the elements used for the prepara-

“…T c (onset) transition temperatures of the A, B, C, and D samples are found to be about 86.3 K, 81.6 K, 78.7 K, and 75.2 K, respectively (see Table 1). This phenomenon may be dependent on weak links of the superconducting grains, impurity levels and lattice defects of the doped samples [10][11][12][13]. Moreover, roomtemperature resistivity of samples increases with Ni content.…”

Section: Resultsmentioning

confidence: 99%

Effects of Ni Substitution in Bi-2212 Superconductors

Özkurt

2012

In this study the samples were synthesized from a 2234 stoichiometric composition in order to obtain a large amount of pure 2212-BSCCO. The effects of Ni substitution on the properties of Bi-based Bi 2−x Ni x Sr 2 Ca 1 Cu 2 O y superconductor with x = 0, 0.05, 0.1 and 0.2 were investigated by means of X-ray analysis (XRD), DC electrical resistivity and magnetic-hysteresis loop measurements. It has been found that the T c (onset) transition temperature does not change independently of Ni content. In addition, J c values of the samples were calculated from the hysteresis loop measurement by using Bean's model, showing that J c decreases with increasing Ni substitution.