Effect of Magnetic Field Direction on Magnetoresistivity, Activation Energy, Irreversibility and Upper Critical Field of Bi-2212 Thin Film Fabricated by DC Sputtering Method

Abstract

This study aims to investigate the effect of magnetic field direction on superconducting properties of Bi-2212 thin film fabricated on MgO (100) substrate using the direct current (DC) magnetron reactive sputtering technique at 100 watt with the aid of magnetoresistivity measurements. The zero resistivity transition temperatures (T c ), irreversibility fields (μ 0 H irr ) and upper critical fields (μ 0 H c2 ) are deduced from the magnetoresistivity versus temperature curves under DC magnetic fields (parallel and perpendicular to c-axis) up to 5 T. Moreover, thermally activated flux flow (TAFF) model is studied for activation energy (U 0 ) values of the sample. It is found that the T c value decreases from 76.4 K to 39.1 K for the applied magnetic field perpendicular to c-axis (μ 0 H ⊥c-axis); likewise, the T c reduces towards 28.8 K with the increase in the applied field parallel to c-axis (μ 0 H c-axis). Furthermore, the U 0 values are found to decrease considerably with increasing applied magnetic field. In fact, the U 0 of 134.5 K is obtained to be smallest at 5 T field parallel to the c-axis. Additionally, both the μ 0 H irr and μ 0 H c2 values determined are also observed to reduce with the increase of the applied magnetic field. At absolute zero temperature (T = 0 K), the extrapolation of the μ 0 H irr (T ) and μ 0 H c2 (T ) curves is used to obtain the μ 0 H irr (0) and μ 0 H c2 (0) values of the film, respectively. The inner is found to be about 22.216 T (19.046 T) for the applied field perpendicular (parallel) to c-axis whereas the latter is determined to be about 54.095 T (126.522 T) for the applied field parallel (perpendicular) to c-axis, respectively, as a result of anisotropic behavior of the film prepared. On the other hand, penetration depths (λ) and coherence lengths (ξ ) inferred from μ 0 H irr (0) and μ 0 H c2 (0) values are obtained to be about 38.519 Å (41.601 Å) and 16.147 Å (24.685 Å) in the case of applied field perpendicular (parallel) to c-axis, respectively. Based on all the results, the change of the superconducting properties as a function of the magnetic field direction presents the anisotropy of the sample produced. X-ray diffraction (XRD) and scanning electron microscopy (SEM) examinations are also conducted for microstructural and phase analyses of the film.

Enhanced superconducting performance of melt quenched Bi2Sr2CaCu2O8 (Bi-2212) superconductor

“…Moreover, it is seen that peaks corresponding to planes along [001] direction, are of higher intensity for MQ sample as compared to NM sample. This indicates preferred alignment of grains along c-axis for MQ sample in comparison to NM sample [27]. and is found to be around 63 percent.…”

Effect of Yb-substitution on thermally activated flux creep in the Bi2Sr2Ca1Cu2−xYbxOy superconductors

“…As it is well known temperature is related to the transition of isolated grains to the superconducting state. On the other hand, temperature is related to volume fraction of Bi-2223 phase and/or features of intergranular component [24,[51][52][53]. Therefore, the temperatures close to the onset transition temperature region, the structure is in accordance with the intergrain transitions, and these transitions are not affected by the applied magnetic field due to the absence of flux traps.…”

Infield superconductivity of carbon nanotubes-Cu0.5Tl0.5Ba2Ca2Cu3O10−δ superconductor composites

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