Powder preparation by organic precursor and densification of a high-Tc Bi-based superconductor

Tampieri, Anna; Celotti, G.; Ricciardiello, F.; Russo, G.

doi:10.1016/0921-4534(94)90085-x

Cited by 21 publications

(6 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The use of organic precursors derived from pyrolysis overcomes the problems of homogeneity and stoichiometry control and allows us to prepare the pure (2223) phase in only 24 hours [2]. It was in fact already known [3] that the pyrolysed precursor and the classical mixture of oxides and carbonates, subjected to the same thermal treatments, run along different routes, characterized by different kinetics.…”

Section: -Discussion and Resultsmentioning

confidence: 99%

Anisotropic thermal and mechanical properties of bulk high-T c Bi-based superconductors

et al. 1994

Self Cite

View full text Add to dashboard Cite

Superconducting powders with nominal composition Bil.saPb0.~Srl.91Ca2.0aCu3.060 ~ were prepared by two different routes: by solid-state reaction of the respective oxides and carbonates and by pyrolysis of organic precursors. Highly dense superconducting specimens characterized by textured microstructure were prepared by hot pressing. The thermal-expansion coefficients of different typologies of samples were measured by dilatometric tests in both directions parallel and perpendicular to the pressure application direction. Structural rearrangements occurring during thermal treatments were studied. As regards mechanical characterization, microhardness, flexural strength and fracture toughness were evaluated and related to the microstructure anisotropic degree of the sample.

show abstract

Section: -Discussion and Resultsmentioning

confidence: 99%

Anisotropic thermal and mechanical properties of bulk high-T c Bi-based superconductors

et al. 1994

Self Cite

View full text Add to dashboard Cite

show abstract

“…The synthesis methodologies are described elsewhere [5]. Superconducting powders were Manuscript received September 14, 1998. thereinafter indicated as X, Y and Z, they were chosen, on the basis of previous experiments, in order to compare results obtained by adjusting a standard starting stoichiometry and taking into account that partial melting is involved in the proposed ceramic process.…”

Section: Methodsmentioning

confidence: 99%

A multi-step process to improve texturing and transport current in BSCCO (2223) superconductors

Tampieri

Celotti

Calestani³

1999

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

Abslruct-Bulk BSCCO(2223) was prepared by a multi-step process (high cold pressing + pressureless sintering + hot-forging): the final density of the samples exceeds 95% and the orientation factor increases up to *86%.It was found that the process phenomenology is strictly linked to the starting powder stoichiometry and characteristics: when composition is very near to the theoretical (2223), effects of secondary phase extrusion are observed during hot-forging, yielding a purification and inhibition of (2212) formation, accompanied by an appreciable increase of J, respect to hotpressed samples. When Ca/Sr ratio is considerably >1, recrystallisation of (2223) from the liquid takes place, with a remarkable improvement of critical current density (Jc > lo4 A/cm2). In this case, the non-superconducting secondary phases act as intrinsic oxygen reservoir. Finally, when composition diverges even more from (2223) (CdSr >>1 and Cu excess), the formation of too many precipitates of non-superconducting phases hinders the texturing process and more in general deteriorates the intergranular properties.

show abstract

“…Superconducting powders with different compositions near to (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O x were prepared by solidstate reaction, pyrolysis and sol-gel methods. The synthesis methodologies are described elsewhere [4,5]. Superconducting powders were uniaxially cold pressed at 1 GPa, then the compact bodies were sintered without applied pressure at 858 • C for 5 h (850 • C in the case of sol-gel powders).…”

Section: Methodsmentioning

confidence: 99%

Bi-2223 bulk superconductor with oriented texture and high transport critical current

Tampieri¹,

Celotti²

2000

Supercond. Sci. Technol.

View full text Add to dashboard Cite

BSCCO (2223) superconducting powders were prepared by three different techniques (solid state, pyrolysis and sol-gel) and with three different stoichiometries, essentially based on variations of the Ca/Sr ratio and the Cu concentration. Pressureless sintering was performed on cold uniaxially pressed (1 GPa) samples, avoiding the drawbacks connected with hot pressing; different hot-forging cycles were then applied to attain a greater density and orientation factor. It was found that the process phenomenology is strictly linked to the powder starting stoichiometry: when the composition is very near to the theoretical (2223), the effects of the secondary phase extrusion are observed during hot forging, yielding a purification and inhibition of ( 2212) formation accompanied by an appreciable increase of J c with respect to the hot-pressed samples. On the other hand, when the Ca/Sr ratio is considerably greater than one and the Cu excess is low, recrystallization of ( 2223) from the liquid takes place, with a remarkable improvement of the critical current density (J c > 10 4 A cm −2 ).

show abstract

Powder preparation by organic precursor and densification of a high-Tc Bi-based superconductor

Cited by 21 publications

References 13 publications

Anisotropic thermal and mechanical properties of bulk high-T c Bi-based superconductors

Anisotropic thermal and mechanical properties of bulk high-T c Bi-based superconductors

A multi-step process to improve texturing and transport current in BSCCO (2223) superconductors

Bi-2223 bulk superconductor with oriented texture and high transport critical current

Contact Info

Product

Resources

About