Influence of oxygen pressure on critical current density and magnetic flux pinning structures in YBa
                    2
                    Cu
                    3
                    O
                    
                      7−
                      x
                    
                    fabricated by chemical solution deposition

The major limitation of Bi-system superconductor applications is the intergrain weak links and weak flux pinning capability producing low critical current density of the Bibased phases. In order to enhance these characteristics and other superconducting properties, effective flux pinning centers are introduced into high temperature superconductors. In this work, different weight percentages of ZnO nano oxide were introduced at the final stage of the Bi1.8Pb0.4Sr2Ca2Cu3O10-y superconductor preparation process. Phase characterization was completed by X-ray diffraction (XRD). Exact constitution of the samples was determined using particle induced X-ray emission (PIXE). Granular and microstructure were investigated using scanning electron microscopy (SEM). Electrical resistivity as function of the temperature was carried to evaluate the relative performance of samples, and finally, E-J characteristic curves were obtained at 77K. Using 0.4 ZnO weight percentage, the electrical and granular properties were greatly enhanced, indicating more efficient pinning mechanisms. A critical current density of 949 A/cm2 was obtained which represents more than twice the value obtained for the pure sample (Jc= 445 A/cm2).

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Flux pinning and improved critical current density in superconducting boron doped diamond films

Journal of Physics Communications ◽

10.1088/2399-6528/aab39f ◽

2018 ◽

Vol 2 (4) ◽

pp. 045015 ◽

Cited By ~ 1

Author(s):

Dinesh Kumar ◽

Shibnath Samanta ◽

K Sethupathi ◽

M S Ramachandra Rao

Keyword(s):

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Flux Pinning ◽

Diamond Films ◽

Boron Doped Diamond ◽

Boron Doped

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Anisotropic critical current density and flux pinning mechanism of Fe1+yTe0.6Se0.4 single crystals

Superconductor Science and Technology ◽

10.1088/1361-6668/ac3632 ◽

2021 ◽

Author(s):

Yongqiang Pan ◽

Nan Zhou ◽

Bencheng Lin ◽

Jinhua Wang ◽

Zengwei Zhu ◽

...

Keyword(s):

Critical Current Density ◽

Single Crystals ◽

Critical Current ◽

Current Density ◽

Flux Pinning ◽

Magnetic Hysteresis ◽

Magnetic Hysteresis Loop ◽

Pinning Force ◽

Magnetization Relaxation ◽

Pinning Mechanism

Abstract Fe1+yTe0.6Se0.4 has considerable application potential due to its large critical current density (J c) and high upper critical magnetic field (H c2). However, the uncertainty of the anisotropy of J c and the unclear flux-pinning mechanism have limited the application of this material. In this study, the J c in three directions were obtained from magnetic hysteresis loop measurements. A large anisotropy of J c ab /J c c ~ 10 was observed, and the origin of the anisotropy was discussed in details. Flux pinning force densities (F p) were obtained from J c, and a non-scaling behavior was found in the normalized pinning force f p[F p/F p-max] versus the normalized field h[H/H c2]. The peaks of pinning force shift from a high h to a low h with increasing temperature. Based on the vortex dynamics analysis, the peak shift was found to originate from the magnetization relaxation. The J c and F p at critical states free from the magnetic relaxation were regained. According to the Dew-Hughes model, the dominant pinning type in Fe1+yTe0.6Se0.4 clean single crystals was confirmed to be normal point pinning.

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