Method of fabricating thallium-containing ceramic superconductor

Details Method of fabricating thallium-containing ceramic superconductor Method of fabricating thallium-containing ceramic superconductor

1992-10-21

1994-07-26

Lieberman, Paul

Superconductor technology: apparatus, material, process

Processes of producing or treating high temperature...

Shaping or consolidating

505725, 505742, 505783, 505501, C01F 1102, C01G 302, C01G 1500, H01L 3924

Patent

active

053327217

ABSTRACT:
An improved technique for the fabrication of thallium-based superconducting oxides, and particularly Tl:Ba:Ca:Cu:O 2223 oxides, is described which allows production of very pure superconductors (>95% 2223 phase) having excellent structural characteristics. The method of the invention involves first forming a self-sustaining body of starting oxides and subjecting this body to a sintering technique wherein the temperature of the body is gradually raised to a maximum level of about 850.degree.-930.degree. C., followed by maintaining the body at this temperature for a period of about 48 hours. The body is then slowly cooled to avoid distortion and loss of superconducting character. Most preferably, the sintering is a two-stage operation, wherein the body is first heated a relatively low rate (e.g., 1.degree.-10.degree. C./min.) to a temperature of about 650.degree.-750.degree. C., followed by faster heating at a higher rate to achieve the maximum sintering temperature. Cooling is likewise staged, involving slow cooling at a rate of about O.1.degree.-5.degree. C./min. until a temperature of about 600.degree.-650.degree. C. is reached, where the body is maintained at this temperature for about 5-20 hours. Final cooling is allowed to occur naturally down to ambient temperature.

REFERENCES:
patent: 4894361 (1990-01-01), Subramanian
patent: 4929594 (1990-05-01), Gopalakrishnan et al.
patent: 4988668 (1991-01-01), Engler
patent: 5021400 (1991-06-01), Block
patent: 5082825 (1992-01-01), Hermann
Takahashi et al. "Preparation and properties of Tl-Ca-Ba-Cu-O" Jap. Jnl. Appl. Phys. vol. 27(8) Aug. 1988 pp. L1457-L1459.
Torardi "Crystal structure of Tl.sub.2 Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10, a 125K Superconductor" Science vol. 240 Apr. 29, 1988 pp. 631-633.
Liang "Crystal structures and superconductivity of . . . " Physica C vol. 156 Nov. 1, 1988 pp. 616-624.
Lin, et al, "Process and Resistivity . . . in Tl-Ca-Ba-Cu-O," Jul., 1988, Jap. Jr. of Appl. Phy., vol. 27, No. 7, pp. L1206-L1208.
Wu, et al, "Synthesis of TlCaBaCuO . . . Mixtures", 1989, Physica C 161, pp. 302-312.
Morosin, et al, "Crystal Structure of TlCaBaCuO," Nov. 1, 1988, Physica C 156, pp. 587-591.
Hibble, et al, "Relationship Between . . . In The TlBaCaCuO Superconductors," Nov. 1, 1988, Physica C 156, pp. 604-606.

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