Synthesis and characterization of high-T sub c superconductors in the Ti-Ca-Ba-Cu-O system--

Journal Article · Mon May 01 00:00:00 EDT 1989 · International Journal of Modern Physics B; (USA)

DOI:https://doi.org/10.1142/S0217979289000543· OSTI ID:7007751

Bansal, N P ^[1]; Farrell, D E ^[2]

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1. National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
2. Case Western Reserve Univ., Cleveland, OH (USA). Dept. of Physics

This paper reports an effort to synthesize the high-T{sub c} superconducting phase in the thallium system two nominal compositions, Tl{sub x}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10} and Tl{sub 1}Ca{sub 3}Ba{sub 1}Cu{sub 3}O{sub 8.5}, have been investigated for superconductivity as a function of the sintering temperature, time, atmosphere, and quench rate. Samples have been characterized by electrical resistivity measurements, X-ray diffraction, and scanning electron microscopy. Samples of starting composition Tl{sub 2}Ca{sub 2}Ba{sub 2}O{sub 10} fired in air at 860-900{degrees}C and rapidly quenched showed T{sub c} (R = O) of 96-107 K. In contrast, specimens of starting composition Tl{sub 1}Ca{sub 3}Ba{sub 1}O{sub 8.5} when baked at 900{degrees}C and slow cooled in oxygen were superconducting at {approx gt} 116 K and consisted of Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10 + x} as the dominant phase. The authors results also show that, in contrast to the case of YBa{sub 2}Cu{sub 3}O{sub 7 {minus} x}, doping with a small concentration of fluorine sharpens the resistive transition and produces large T{sub c} increase in thallium-based superconductors.

• OSTI ID: 7007751
• Journal Information: International Journal of Modern Physics B; (USA), Vol. 3:5; ISSN 0217-9792
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
SUPERCONDUCTORS
SYNTHESIS
THALLIUM COMPOUNDS
SUPERCONDUCTIVITY
BARIUM OXIDES
CALCIUM OXIDES
CHEMICAL COMPOSITION
COPPER OXIDES
ELECTRIC IMPEDANCE
FLUORINATION
HIGH TEMPERATURE
OXYGEN
QUENCHING
SCANNING ELECTRON MICROSCOPY
SINTERING
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TRANSITION TEMPERATURE
VACANCIES
X-RAY DIFFRACTION
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
COPPER COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELEMENTS
FABRICATION
HALOGENATION
IMPEDANCE
MICROSCOPY
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POINT DEFECTS
SCATTERING
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
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