Laser Processing and Characterization of High-Tc Superconductors

ABSTRACTRaman spectra of several samples of YBa2Cu3O7 presented, correlated with resistivity and structural data, and compared with previous results. Laser heating to ∼1100°C in air is shown to produce a surface layer of Y2O3 and Y2BaCuO5. Similar heating of La2−x(Sr,Ba)xCuO4 produces a layer of La2O3. All of these compounds are readily identified by their Raman spectra.

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Noncontact methods used for characterization of high‐Tc superconductors

Review of Scientific Instruments ◽

10.1063/1.1139857 ◽

1988 ◽

Vol 59 (4) ◽

pp. 659-661 ◽

Cited By ~ 24

Author(s):

J. D. Doss ◽

D. W. Cooke ◽

C. W. McCabe ◽

M. A. Maez

Keyword(s):

High Tc Superconductors ◽

High Tc

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SYNTHESIS AND CHARACTERIZATION OF HIGH-Tc SUPERCONDUCTORS IN THE Tl–Ca–Ba–Cu–O SYSTEM

International Journal of Modern Physics B ◽

10.1142/s0217979289000543 ◽

1989 ◽

Vol 03 (05) ◽

pp. 733-741

Author(s):

NAROTTAM P. BANSAL ◽

D. E. FARRELL

Keyword(s):

Sintering Temperature ◽

Resistive Transition ◽

X Ray Diffraction ◽

High Tc Superconductors ◽

High Tc ◽

X Ray ◽

Resistivity Measurements ◽

Temperature Time ◽

Dominant Phase

In an effort to synthesize the high-T c superconducting phase in the thallium system, two nominal compositions, Tl 2 Ca 2 Ba 2 Cu 3 O 10 and Tl 1 Ca 3 Ba 1 Cu 3 O 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 2 Ca 2 Ba 2 Cu 3 O 10 fired in air at 860–900°C and rapidly quenched showed T c (R = 0) of 96–107 K. In contrast, specimens of starting composition Tl 1 Ca 0 Ba 1 Cu 3 O 8.5 when baked at 900°C and slow cooled in oxygen were superconducting at ≥ 116 K and consisted of Tl 2 Ca 2 Ba 2 Cu 3 O 10+x as the dominant phase. Our results also show that, in contrast to the case of YBa 2 Cu 3 O 7−x, doping with a small concentration of fluorine sharpens the resistive transition and produces large T c increase in thallium-based superconductors.

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Synthesis and characterization of Pr substituted Gd-123 high-Tc superconductors

Cerâmica ◽

10.1590/s0366-69132012000300016 ◽

2012 ◽

Vol 58 (347) ◽

pp. 381-387 ◽

Cited By ~ 1

Author(s):

V. R. Huse ◽

V. D. Mote ◽

Y. Purushotham ◽

B. N. Dole

Keyword(s):

Oxygen Deficiency ◽

Resistivity Measurement ◽

Charge Carriers ◽

Electrical Resistivity Measurement ◽

Chemical Formula ◽

Curie Constant ◽

High Tc Superconductors ◽

High Tc ◽

Magnetic Pair

High Tc superconducting materials with chemical formula Gd1-xPr xBa2Cu3O7-δ, where x = 0.0, 0.1, 0.2 and 0.3 were prepared by ceramic route. XRD studies confirm the orthorhombic pervoskite structure. Electrical resistivity measurement shows that Tc decreases with increasing Pr concentration. Copper valency and oxygen content decreasing with increasing Pr content. Value of n(CuO2) decreases with increasing x and oxygen deficiency (δ) has a linear dependence with (2x+δ). SQUID investigation reveals that Bohr magneton number and Curie constant are decreasing with increasing Pr concentration. Annihilation of superconductivity may be owing to reduction in CuO2 charge carriers or magnetic pair breaking.

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ChemInform Abstract: High-Tc Superconductors: Selective Preparation and Characterization of Tetragonal and Orthorhombic (93 K Superconductor) Phases of YBa2Cu3O7-x.

ChemInform ◽

10.1002/chin.198738040 ◽

1987 ◽

Vol 18 (38) ◽

Author(s):

A. M. KINI ◽

U. GEISER ◽

H.-C. I. KAO ◽

K. D. CARLSON ◽

H. H. WANG ◽

...

Keyword(s):

High Tc Superconductors ◽

High Tc

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Microstructure of a Y2Ba2Cu3O7-Σ superconductor pellet prepared by shock consolidation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010682x ◽

1988 ◽

Vol 46 ◽

pp. 952-953

Author(s):

R. F. Antrim ◽

J. Marti ◽

Z. Iqbal

Keyword(s):

Shock Wave ◽

High Temperature ◽

Thin Film Deposition ◽

Film Deposition ◽

Nominal Composition ◽

High Tc Superconductors ◽

High Tc ◽

Shock Compaction ◽

High Pressure High Temperature

R&D in high Tc superconductors encompasses two broad areas, namely, 1) synthesis and characterization of high Tc superconducting powders and 2) consolidation of the powders into useful parts. In the latter area, techniques such as thin film deposition, high temperature sintering of the powders and continuous casting are being pursued by various groups. Another technique which could prove useful in the fabrication of larger pieces is that of shock compaction. In this approach, explosives are used to propel a piston, resulting in a shock wave which leads to high pressure- high temperature consolidation of the powder. In this report we examine the microstructure that results when a superconducting powder was consolidated into a pellet using the shock-loading technique.The nominal composition of the starting powder was Y1Ba2Cu3O7δ (“123”). Explosives were used to create a shock-wave with an estimated peak pressure of 60 GPa and temperatures of about 800°C.

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