Aligned Sintered Compacts of RBa2Cu3O7−x (R=Dy, Er, Eu, Gd, Ho, Y)

1987 ◽  
Vol 99 ◽  
Author(s):  
R. H. Arendt ◽  
A. R. Gaddipati ◽  
M. F. Garbauskas ◽  
E. L. Hall ◽  
H. R. Hart ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Single Crystal ◽  
Critical Current ◽  
Current Density ◽  
Critical State ◽  
Magnetic Measurements ◽  
Magnetic Hysteresis ◽  
X Ray ◽  
Significant Alignment ◽  
Magnetically Aligned

ABSTRACTSintered compacts of magnetically aligned single-crystal particles have been studied by x-ray, microscopy, and magnetic measurements. Though significant alignment and very anisotropie magnetic hysteresis were obtained, the magnitude of the hysteresis indicates, through the critical state model, that the bulk critical current density remains low.

A SDUTY OF SUPERCONDUCTING OXIDE Y-Ba-Cu-Sn-O

1987 ◽  
Vol 01 (02) ◽  
pp. 277-280 ◽  
Author(s):  
Xin Jin ◽  
Huimin Shao ◽  
Guiqin Wang ◽  
Mu Lu ◽  
Hanhe Zhang ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Magnetic Hysteresis ◽  
X Ray Diffraction ◽  
X Ray

A high-Tc superconductor YBa2Cu3 Snx07+z was characterized. We observed the existence about 90K superconductivity in variety of compositions. The samples were examined by x-ray diffraction , Mössbauer, SEM and EDS. Their structure are still ABO3 perovskite but part of Cu atoms are displaced by Sn. It was observed that when the x increased the critical current density were increased based on the measurements of magnetic hysteresis.

Effects of Nano-Sized BN Doping on the Phase Formation, Tc and Critical Current Density of MgB2 Superconductor

2005 ◽  
Vol 23 ◽  
pp. 113-116 ◽  
Author(s):  
S. Soltanian ◽  
M. Delfany ◽  
X.L. Wang ◽  
M.J. Qin ◽  
H.K. Liu ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Magnetic Measurements ◽  
Magnetic Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measurement Results ◽  
Diffraction Patterns ◽  
Synthesized Materials

MgB2 polycrystalline bulk samples with additions of 0, 5, 10 and 20% wt.% nano-sized BN powders were prepared using the reaction in-situ method. All the samples were sintered at 850°C for 1h in Ar. All the samples were characterized by X-ray diffraction, scanning electron microscopy (SEM) and magnetic measurements. The X-ray diffraction patterns show that the BN does not react with Mg and B during the heat treatment and remains as a separate phase. The synthesized materials thus contain two separate BN and MgB2 phases. In addition, the samples contain a small, almost constant amount of MgO. SEM shows that the samples contain MgB2 grains with average grain sizes of about 250 nm. Magnetic measurement results show that the critical current density and irreversibility fields decrease slightly as the BN level increases. The Tc drops slightly from 38.9 to 38.2 K and has a sharp transition with a transition width of less than 1 K. The field dependence of Jc for all the samples is also presented.

STUDY OF THE TEXTURING IN BSCCO-AG TAPES THROUGH MAGNETIC MEASUREMENTS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 3159-3164
Author(s):  
C. FERDEGHINI ◽  
M. R. CIMBERLE ◽  
G. GRASSO ◽  
P. GUASCONI ◽  
A. MALAGOLI ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Magnetic Measurements ◽  
Texture Evolution ◽  
Rolling Direction ◽  
Longitudinal Direction ◽  
Magnetic Method ◽  
Superconducting Compounds

We have developed a method that allows, by a simple set of magnetic measurements, to study the texturing of the grains inside a BSCCO-Ag tape. Because the texture is anisotropic we define the angle ϑ L that identifies the mean grain misalignment angle with respect to the tape surface in longitudinal direction (i.e. rolling direction) and the angle ϑ T in transverse direction. The technique is based on the assumption that, because of the very high anisotropy of the critical current density in BSCCO superconducting compounds, the magnetic moment is essentially generated by the current circulating in the a-b planes of the BSCCO grains. The different magnetisation cycles, measured when the orientation of the magnetic field with respect to the tape surface is changed, depend only on the grain orientation inside the tape, which determines the effective magnetic field component normal to the a-b planes of the grains. Here we present the texture evolution of the BSCCO grains inside silver sheated multifilamentary tape starting from the initial steps of the mechanical deformation up to the final heating stage. The results obtained from the magnetic method are compared with those obtained with other methods, i.e. X-ray diffraction and critical current density anisotropy. Also results obtained on samples prepared in different way will be presented.

Effect of ZnO Nano-Oxide Addition on the Superconducting Properties of the (Bi.Pb)2223 Phase

2011 ◽  
Vol 324 ◽  
pp. 241-244 ◽  
Author(s):  
R. Mawassi ◽  
R. Awad ◽  
Mohamad Roumie ◽  
M. Kork ◽  
I. Hassan
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
High Temperature Superconductors ◽  
Weak Links ◽  
Superconducting Properties ◽  
X Ray ◽  
Weight Percentage ◽  
Nano Oxide

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).

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

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.

Analysis of Electromagnetic Properties of Bulk Superconductors

2021 ◽  
Vol 21 (9) ◽  
pp. 4941-4943
Author(s):  
Sang Heon Lee
Keyword(s):  
Critical Current Density ◽  
Single Crystal ◽  
Critical Current ◽  
Current Density ◽  
Magnetic Force ◽  
Electromagnetic Properties ◽  
Weak Links ◽  
Metallic Silver ◽  
Bulk Superconductor ◽  
Slow Cooling

In the present study, a YBa2Cu3O7−y bulk superconductor added with 5~10 wt% Ag was fabricated employing Sm123 as a seed to produce a superconductive single crystal. Metallic silver was added to the single crystal of YBa2Cu3O7−y to remove defects such as cracks and pores. Electromagnetic properties of the bulk superconductor at 77 K were analyzed based on relationships of magnetic levitation, trapped magnetic force, and critical current density. The critical current density of the superconductor at 77 K and 0 T was 3.53 × 104 A/cm2. Discontinuous points in the distribution of magnetic field lines were not observed, implying that these two specimens grew well as a single crystal without specific weak links. For the growth of a superconductive nano crystal employing slow cooling at temperature of formation of 123 phase, superconductive nano crystals were aligned in a-b direction, the direction of peak current flow. The peak value of the trapped magnetic force of the YBa2Cu3O7−y superconductor specimen was 3.23 kG. Using the FC method, peak forces of attraction and repulsion were 21.696 N and 70.168 N, respectively.

scholarly journals Critical current density, vortex dynamics, and phase diagram of single-crystal FeSe

2015 ◽  
Vol 92 (14) ◽  
Author(s):  
Yue Sun ◽  
Sunseng Pyon ◽  
Tsuyoshi Tamegai ◽  
Ryo Kobayashi ◽  
Tatsuya Watashige ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Critical Current Density ◽  
Single Crystal ◽  
Critical Current ◽  
Current Density ◽  
Vortex Dynamics

Effect of Co0.5Ni0.5Fe2O4 Nanoparticles Addition in Ag-Sheathed Bi-2223 Superconductor Tapes Prepared by Co-Precipitation Method

2020 ◽  
Vol 981 ◽  
pp. 59-65
Author(s):  
Muhammad Hafiz Mazwir ◽  
Bryan Andrew Balasan ◽  
Farah Hanani Zulkifli ◽  
Roslan Abd-Shukor
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Magnetic Oxide ◽  
Pinning Centers ◽  
X Ray ◽  
Co Precipitation ◽  
Powder In Tube

Effect of complex magnetic oxide Co0.5Ni0.5Fe2O4 (CNFO) nanoparticles addition in (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (Bi-2223) superconductor tapes was investigated. Ultrafine Bi-2223 powder precursor was prepared via co-precipitation method and was added with 0.01 – 0.05 wt.% Co0.5Ni0.5Fe2O4 nanoparticles during the final heating stage. The sample with 0.01 wt.% addition, Bi-2223(CNFO)0.01 was found to have the highest critical current density, Jc. This sample were then chosen to be fabricated into Ag-sheathed superconductor tapes using the powder-in-tube (PIT) method. The tapes were sintered for 50 and 100 h at 845 °C. The phase, microstructure and Jc of the samples were determined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and four point probe, respectively. Jc of Ag-sheathed Bi-2223(CNFO)0.01 tapes sintered for 100 h was 19830 A/cm2 at 30 K and 3970 A/cm2 at 77 K compared to tapes without addition which showed a much lower Jc(6370 A/cm2 at 30 K). This study showed that CNFO nanoparticles could act as an effective flux pinning centers to enhance the critical current density in the Bi-2223 superconductor.

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