scholarly journals Effect of Nanosized NiF2Addition on the Transport Critical Current Density of Ag-Sheathed (Bi1.6Pb0.4)Sr2Ca2Cu3O10Superconductor Tapes

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
M. Hafiz ◽  
R. Abd-Shukor
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Flux Line ◽  
Transport Critical Current Density ◽  
Pinning Centers ◽  
Sintering Time ◽  
Line Network ◽  
Powder In Tube

We report the effect of NiF2(10 nm) additions on the transport critical current density,Jcof (Bi1.6Pb0.4)Sr2Ca2Cu3O10/Ag sheathed superconductor tapes. Pellets of (Bi1.6Pb0.4)Sr2Ca2Cu3O10(NiF2)x(x=0–0.05 wt.%) superconductor were prepared using the acetate coprecipitation method. The sample with 0.04 wt.% addition of NiF2exhibited the highestJc. Ag-sheathed (Bi1.6Pb0.4)Sr2Ca2Cu3O10(NiF2)0.04superconductor tapes were fabricated using the powder-in-tube (PIT) method and sintered at 845°C for 50 and 100 h.Jcof nonadded tapes at 30 K sintered for 50 and 100 h was 6370 and 8280 A/cm2, respectively.Jcof (Bi1.6Pb0.4)Sr2Ca2Cu3O10(NiF2)0.04/Ag tape at 30 K sintered for 50 and 100 h was 14390 and 17270 A/cm2, respectively. In magnetic fields (0 to 0.7 T),Jcof the NiF2added tapes was also higher compared with the nonadded tape indicating that NiF2nanoparticles can act as effective flux pinning centers and longer sintering time improved the microstructure. A steeper increase inJcwas observed below 60 K in the NiF2added tapes which coincided with the Neel temperature,TNof nanosized NiF2(60 K). The pronounced enhancement ofJcwas attributed to the strong interaction between flux line network and the antiferromagnetic NiF2belowTN.

Transport Critical Current Density and Flux Pinning Enhancement in Nano-Sized PbO and HfO2 Added (Bi1.6Pb0.4)Sr2Ca2Cu3O10 Superconductor

2015 ◽  
Vol 1108 ◽  
pp. 85-90
Author(s):  
Nabil A.A. Yahya ◽  
R. Abd-Shukor
Keyword(s):  
Particle Size ◽  
Transition Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Homogeneous Distribution ◽  
Transport Critical Current Density ◽  
Superconducting Properties ◽  
Pinning Centers

A comparative study on the effect of PbO (10-30 nm) and HfO2 (60-80 nm) additions on the superconducting properties of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 ((Bi,Pb)-2223) superconductor in the bulk form was carried out. The structure and the microstructure of prepared samples were examined by powder XRD and SEM, respectively. The transition temperature Tc and critical current density Jc was determined by standard dc four-probe method. SEM micrographs showed a homogeneous distribution of Pb and Hf in the samples. It was observed that PbO and HfO2 additions enhanced Jc for all added samples. Jc was the highest for x= 0.05 wt. % of PbO (1130 mA/cm2 at 77 K and 1930 mA/cm2 at 30 K) and HfO2 (900 mA/cm2 at 77 K and 1760 mA/cm2 at 30 K) addition. This study showed that the addition of PbO and HfO2 nanopowder provided extra flux pinning centers in the (Bi, Pb)-2223. PbO with smaller particle size showed higher Jc compared with HfO2 which has a larger particle size.

Effect of Various C Sources Co-Doping on Transport Critical Current Density and Grains-Connectivity of MgB2/Fe Tapes

2013 ◽  
Vol 745-746 ◽  
pp. 214-218
Author(s):  
Xi Feng Pan ◽  
Guo Yan ◽  
Xiang Hong Liu ◽  
Yong Feng ◽  
Ping Xiang Zhang ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Malic Acid ◽  
Flux Pinning ◽  
Transport Critical Current Density ◽  
Co Doping ◽  
The Poor ◽  
Powder In Tube

In this paper, we have prepared a series of Fe sheathed MgB2 tapes with SiC, Malic acid and C9H11NO mono-and co-doping by in-situ powder-in-tube (PIT) method, and studied the effects of various C sources co-doping on transport critical current density and flux pinning of MgB2/Fe tapes. The results suggest by various C sources co-doping, the amount of C substitution for boron largely increase, comparing to SiC, Malic acid or C9H11NO mono-doped sample. For MgB2/Fe tapes with 5 mol% SiC+10 wt% Malic acid and 4 wt% C9H11NO+10 wt% Malic acid co-doping, the transport Jc at 4.2 K and 10 T are 14.8 and 13.5 kA/cm2, respectively, which are clearly higher than the Jc of these dopants mono-doped samples. Furthermore, it is found that at the 4 wt.% C9H11NO doped MgB2, the poor in-field Jc should be attributing to the cracks at grains boundary, which results in the bad grains-connectivity.

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.

Effects of Tin Addition to the Tl-Based 1223 Superconducting System

1998 ◽  
Vol 12 (04) ◽  
pp. 131-141 ◽  
Author(s):  
Y. T. Wang ◽  
A. M. Hermann
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Temperature Drop ◽  
Superconducting Phase ◽  
Transport Critical Current Density ◽  
X Ray Diffraction ◽  
Pinning Centers ◽  
Magnetization Data ◽  
A Minor

Polycrystalline samples of Tl-based-1223 superconducting system were prepared with tin-addition to form ( Tl 0.5 Pb 0.5) Sn x Sr 1.6 Ca 2.4 Cu 3 O y, for x=0–0.3. X-ray diffraction data showed the presence of a minor 1212 phase and impurities which increased with increasing x while the samples without addition of tin, x=0, were nearly single phase of Tl,Pb-1223. The effects of tin addition to Tl,Pb-1223 on the magnetic properties were studied by dc susceptibility and hysteresis magnetization measurements. The magnetic results revealed a significant enlargement of hysteresis magnetization in tin-added samples with an onset transition temperature drop of only 1–4 K. According to recent measurements, the intragrain Jc reflects the transport critical current density in high field region. The critical current density in Tl,Pb-1223 was enhanced by as much as ten-times by tin-addition. An electron micro-probe technique was employed to locate the added tin in the samples, but Sn incorporated into the superconducting phase was below detectability. The variation in Tc with Sn addition and a reduction in pinning strength at Sn concentration above x=0.05 show that the enhanced pinning is due to introduction of pinning centers into the superconducting phase even though micro-probe analysis indicates that most of the Sn is present in a nonsuperconducting phase. The field dependence and time dependence of the magnetization data showed an increased concentration of pinning centers without a change in pinning energy.

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