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

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.

Download Full-text

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.981.59 ◽

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.

Download Full-text

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1108.85 ◽

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.

Download Full-text

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

Advances in Materials Science and Engineering ◽

10.1155/2015/146476 ◽

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.

Download Full-text

Transport Critical Current Density of (Bi1.6Pb0.4)Sr2Ca2Cu3O10Ceramic Superconductor with Different Nanosized Co3O4Addition

Advances in Condensed Matter Physics ◽

10.1155/2014/498747 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Nur Jannah Azman ◽

Huda Abdullah ◽

Roslan Abd-Shukor

Keyword(s):

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Diffraction Method ◽

Solid State Reaction Method ◽

Small Addition ◽

Transport Critical Current Density ◽

X Ray Diffraction ◽

Conventional Solid State Reaction ◽

X Ray

The effect of different nanosized Co3O4(10, 30, and 50 nm) addition on the Bi1.6Pb0.4Sr2Ca2Cu3O10(Co3O4)xsuperconductor withx=0–0.05 wt.% has been investigated using X-ray diffraction method, scanning electron microscopy, transition temperature, and critical current densityJcmeasurements. The samples were prepared by the conventional solid-state reaction method. Samples withx=0.01 wt.% Co3O4(10 nm) showed the highestTc-zeroat 102 K. The highestJcwas observed in thex=0.03 wt.% Co3O4(10 nm) andx=0.02 wt.% Co3O4(30 nm) samples. At 77 K,Jcof the 10 nm and 30 nm Co3O4added samples was 6 and 13 times larger than the nonadded samples, respectively. Small addition of Co3O4nanoparticles in the Bi1.6Pb0.4Sr2Ca2Cu3O10(Bi-2223) samples enhanced the critical current density and the phase formation. The larger Co3O4nanoparticle (50 nm) had a greater degradation affect on superconductivity of the Bi-2223 phase.

Download Full-text