EFFECTS OF MgO AND Al2O3 ADDITIONS ON THE FORMATION OF THE HIGH Tc PHASE AND SUPERCONDUCTING PROPERTIES IN THE Bi-Pb-Sr-Ca-Cu-O CERAMIC SYSTEM

Abstract(Bi, Pb)-Sr-Ca-Cu-O ‘2223’ wires with varying Bi/Pb ratios and sinter times have been investigated by parallel physical measurements and analytical electron microscopy. The numbers of phases present, their relative amounts, compositions and structures are reported and correlated with the superconducting properties. In particular, the recently reported long period (010) modulation (2b*/q*=7.7) is found to be connected with the “2223” high Tc phase.

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Evolution of the High Tc Phase in Rapidly Solidified Bi-Ca-Sr-Cu Oxides

MRS Proceedings ◽

10.1557/proc-169-329 ◽

1989 ◽

Vol 169 ◽

Author(s):

A. Asthana ◽

P.D. Han ◽

Z. Xu ◽

L. Chang ◽

D.A. Payne ◽

...

Keyword(s):

Rapid Solidification ◽

Heat Treatments ◽

Processing Conditions ◽

Superconducting Properties ◽

High Tc ◽

High Tc Phase ◽

Rapidly Solidified

AbstractMaterials in the system Bi-Ca-Sr-Cu-O were prepared by rapid solidification. Emphasis was placed on optimizing processing conditions for enhancement of the high Tc (2223) phase. A number of starting compositions and heat-treatments were investigated. The effect of dopants (such as, Pb, Sb, Ge, Sn) on the stabilization of the high Tc phase was evaluated. Small amounts of Pb and Sb were effective in significantly increasing the 2223 yield. Improvements in superconducting properties as a function of 2223 evolution are discussed with reference to SEM, TEM, XRD and SQUID results.

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Modulated structures in (Bi,Pb)-Sr-Ca-Cu-O films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173443 ◽

1990 ◽

Vol 48 (4) ◽

pp. 62-63

Author(s):

Shozo Ikeda ◽

Hirotoshi Hayakawa ◽

Daniel R. Dietderich

Keyword(s):

Rf Magnetron Sputtering ◽

Potential Method ◽

High Tc ◽

Bscco System ◽

Heat Treated ◽

Modulated Structures ◽

High Tc Phase ◽

Deposited Films ◽

Sputtering System

Pb addition makes easier to form the high Tc phase in the BSCCO system. However, Pb easily vaporized at high temperature. A controlled Pb potential method has been applied to grow the high Tc phase in films. Initially, films are deposited on cleaved MgO substrates using an rf magnetron sputtering system. These amorphous as-deposited films are heat treated in a sealed gold capsule along with a large pellet of Pb-added BSCCO. Details of the process and characterization of the films have been reported elsewhere (1). Films trated for 0.5h at 850° C contain mainly the low Tc phase with a small amount of the high Tc phase. Hawever, films treated for 3h at 850°C consist mainly of the high Tc phase. This film is superconductive with a Tc(zero) of 106K. The Pb/Bi ratio of the films, analysed by SEM- EDS, are 0.12 and 0.18 for heat tratment times of 0.5 and 3h, respectively. The present study investigates the modulated structures of these films using HREM.

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Synthesis and study the Structural and electrical and mechanical properties of High Temperature Superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ Substituted with nickel oxide for n=3

Ibn AL- Haitham Journal For Pure and Applied Science ◽

10.30526/31.3.2024 ◽

2018 ◽

Vol 31 (3) ◽

pp. 26 ◽

Cited By ~ 4

Author(s):

Laheeb. A. Mohammed ◽

Kareem. A. Jasim

Keyword(s):

Nickel Oxide ◽

High Temperature Superconductor ◽

Sintering Temperature ◽

Concentration Effects ◽

High Tc ◽

Xrd Diffraction ◽

Ni Content ◽

High Tc Phase ◽

Pure Phases ◽

Critical Temperature Tc

on this research is to study the effect of nickel oxide substitution on the pure phases superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ (n=3) where x=(0,0.2,0.4,0.6,0.8.and 1.0). The specimens in this work were prepared with used procedure of solid state reaction with sintering temperature 8500C for 24 h .we used technical (4-prob)to calculated and the critical temperature Tc . The results of the XRD diffraction analysis showed that the structure for pure and doped phases was tetragonal with phases high-Tc phase (1223),(1212) and low-Tc phase (1202) and add to the presence of some impure phase. It was noted the value a=b,c the parameter of the lattice increment with the increment of Ni content. The increment of (NiO) concentration effects electrical resistivity, dielectric constant and the hardness.

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