Synthesis and Properties of the High Tc Bi-Pb-Sr-Ca-Cu-O Superconductors

ABSTRACTA single high Tc phase of Bi-Pb-Sr-Ca-Cu-O superconductor was obtained by following proper synthetic conditions:(a)addition of Pb, (b)proper starting composition, (c)codecomposition method, (d)sintering under low oxygen partial pressure and (e)long sintering. The composition analysis showed that every atomic site might be occupied by some element and there might not be defects or excess atoms in the structure. The hole donor in these samples is considered to be Pb on the Bi site and hole concentration seems to be, to some extent, controlled by the Pb content. A phase with four CuO2 layers have possibly grown on the surface of the grains of thi high Tc phase.

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Effect of Oxygen Partial Pressure on Stability of High-Tc Phase in Sintered Bi-Pb-Sr-Ca-Cu-O Superconductos

MRS Proceedings ◽

10.1557/proc-169-349 ◽

1989 ◽

Vol 169 ◽

Author(s):

H.K. Lee ◽

K.W. Lee ◽

D.H. Ha ◽

J.C. Park

Keyword(s):

Phase Transformation ◽

Oxygen Partial Pressure ◽

Partial Pressure ◽

Superconducting Phase ◽

Low Oxygen ◽

X Ray Diffraction ◽

High Tc ◽

X Ray ◽

High Tc Phase ◽

Effect Of Oxygen

AbstractThe effect of oxygen partial pressure on stability of high-Tc phase in Bi-Pb-Sr-Ca-Cu-O system has been investigated using x-ray diffraction, resistivity and a.c. susceptibility measurements. It was found that part of the high-Tc phase in Bi-Pb-Sr-Ca-Cu-O system was transformed into the low-Tc phase (80 K) and insulating phases by heating in the temperature range 600 C to 880°C in O2 of one atmosphere. The original high-Tc phase was restored upon retreatment in a low oxygen partial pressure of 0.1 atmosphere. The reversible superconducting phase transformation is discussed in conjunction with the formation mechanism of the high-Tc phase in Bi-Pb-Sr-Ca-Cu-O system.

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Quantitative evaluation of the oxidation behavior of ZrB2-15 vol.%SiC at a low oxygen partial pressure

Vacuum ◽

10.1016/j.vacuum.2012.04.004 ◽

2013 ◽

Vol 88 ◽

pp. 98-102 ◽

Cited By ~ 9

Author(s):

Ai Momozawa ◽

Rong Tu ◽

Takashi Goto ◽

Yuuki Kubota ◽

Hiroshi Hatta ◽

...

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Quantitative Evaluation ◽

Oxidation Behavior ◽

Low Oxygen

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Surface oxidation of Alloy 617 in low oxygen partial pressure He–CO–CO2 environments at 750–850 °C

Corrosion Science ◽

10.1016/j.corsci.2014.10.042 ◽

2015 ◽

Vol 90 ◽

pp. 529-534 ◽

Cited By ~ 6

Author(s):

G. Gulsoy ◽

G.S. Was

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Surface Oxidation ◽

Low Oxygen ◽

Alloy 617

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Enhanced superconductivity in Nd1+xBa2-xCu3O7+δby low oxygen partial pressure annealing

Journal of Electronic Materials ◽

10.1007/bf02649956 ◽

1994 ◽

Vol 23 (11) ◽

pp. 1117-1120 ◽

Cited By ~ 18

Author(s):

M. J. Kramer ◽

A. Karion ◽

K. W. Dennis ◽

M. Park ◽

R. W. McCallum

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Low Oxygen ◽

Enhanced Superconductivity

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Tensile Properties and Creep Behavior of SiC-Based Fibers under Various Oxygen Partial Pressures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.1333 ◽

2005 ◽

Vol 475-479 ◽

pp. 1333-1336 ◽

Cited By ~ 5

Author(s):

Jan Ji Sha ◽

J.S. Park ◽

Tatsuya Hinoki ◽

Akira Kohyama ◽

J. Yu

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Tensile Properties ◽

Creep Behavior ◽

Elevated Temperatures ◽

Low Oxygen ◽

X Ray Diffraction ◽

Sic Fibers ◽

Partial Pressures ◽

Ar Gas

Three kinds of atmospheres (air, highly-pure Ar and ultra highly-pure Ar gas) with different oxygen partial pressures were applied to investigate the tensile properties and creep behavior of SiC fibers such as Hi-NicalonTM and TyrannoTM-SA. These fibers were annealed and crept at elevated temperatures ranging from1273-1773 K in such environments. After annealing at 1773 K, the room temperature tensile strengths of SiC-based fibers decreased with decreasing the oxygen partial pressure and the near stoichiometric fiber TyrannoTM-SA shows excellent strength retention. At temperatures above the 1573 K, the creep resistance of SiC fibers evaluated by bending stress relaxation (BSR) method under high oxygen partial pressure was lower than that of in low oxygen partial pressure. The microstructural features on these fibers were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

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