The Nature of Flux Pinning in High TC Ceramic Superconductors / Die Wirkungsweise der Flußschlauch-Haftung in Keramik-Hochtemperatur-Supraleitern

1988 ◽  
Vol 79 (5) ◽  
pp. 271-277
Author(s):  
Chalakara V. Narasimha Rao ◽  
Shyam K. Agarwal ◽  
Betanabhatla Jayaram ◽  
Sylvester Takacs ◽  
Anant V. Narlikar
Keyword(s):  
Flux Pinning ◽  
High Tc ◽  
Ceramic Superconductors

STUDIES OF F ON SUPERCONDUCTIVITY IN HIGH-Tc (Bi,Pb)SrCaCu(O,F) SUPERCONDUCTORS

1993 ◽  
Vol 07 (17) ◽  
pp. 1127-1132
Author(s):  
JIANGUO CAI ◽  
XIAOLONG ZHANG ◽  
XIANGHUA ZHOU ◽  
QIN WEI
Keyword(s):  
Critical Current Density ◽  
Flux Pinning ◽  
Weak Link ◽  
Meissner Effect ◽  
Experimental Methods ◽  
Residual Magnetization ◽  
High Tc ◽  
Bean Model ◽  
Pinning Potential ◽  
The Difference

In this article, the experimental results of the superconductivity in high-Tc (Bi,Pb) 2 Sr 2 Ca 2 Cu 3( O y, F x), x = 0–0.84, is described. Its critical current density Jc is about ten times larger than that of undoped F sample undergoing the same technology. The causes for the increase in Jc are studied by several experimental methods. The difference in quantity between Meissner effect and shield effect indicates that the effect on superconductivity is from the weak-link regions of the superconductor grains. SEM shows that F atoms doped in BPSCCO superconductor can make its grains grow larger, arrange regularly, and increase in touch area. These changes strengthen the netty link between grains. The magnitude of residual magnetization of F-doped sample is eight times as large as that of the undoped one. The flux pinning potential U0 is calculated from the Bean model. The U0 in F-doped sample (when H = 64 Oe, x = 0.64) is eight times as large as that in the undoped one.

Magnetic studies of current conduction and flux pinning in high-Tc cuprates: Virgin, irradiated, and oxygen deficient materials

1992 ◽  
Author(s):  
J. R. Thompson ◽  
Yang Ren Sun ◽  
J. G. Ossandon ◽  
D. K. Christen ◽  
H. R. Kerchner ◽  
...  
Keyword(s):  
Flux Pinning ◽  
Magnetic Studies ◽  
High Tc ◽  
Current Conduction ◽  
High Tc Cuprates

A STRUCTURAL CHEMICAL MODEL FOR HIGH Tc CERAMIC SUPERCONDUCTORS

1987 ◽  
Vol 01 (07n08) ◽  
pp. 275-288 ◽  
Author(s):  
S.R. OVSHINSKY ◽  
S.J. HUDGENS ◽  
R.L. LINTVEDT ◽  
D.B. RORABACHER
Keyword(s):  
Electronic Properties ◽  
Oxygen Vacancies ◽  
Oxygen Removal ◽  
Bose Condensation ◽  
Oxidation States ◽  
Chemical Model ◽  
Electrically Conductive ◽  
High Tc ◽  
Ceramic Superconductors ◽  
Mixed Oxidation

A structual chemical model for high Tc ceramic superconductors is proposed in which carriers pairs, coupled through a superexchange process, undergo Bose condensation. In the Y-Ba-Cu-O system, Cu atoms on “chain” sites and “sheet” sites are initially assigned formal oxidation states of +3 and +2, respectively, and “sheet”/“chain” interactions are then introduced to bring about the electrically conductive mixed oxidation state. This model explains the presence of labile oxygen in the “chain” structures, describes the structure of deoxygenated phases exhibiting ordered oxygen vacancies in the “chains”, and allows interpretation of the effects of oxygen removal on magnetic and electronic properties of the material.

High-Tc Ceramic Superconductors Through Oxidation of Mechanically Alloyed Y-Ba-Cu and Bi-Sr-Ca-Cu Powders

1989 ◽  
pp. 281-286
Author(s):  
Shin-ichi Murasaki ◽  
Satoru Taniguchi ◽  
Uichiro Mizutani ◽  
Motohiro Suganuma ◽  
Yuh Yamada
Keyword(s):  
Mechanically Alloyed ◽  
High Tc ◽  
Ceramic Superconductors

MAGNETO-OPTIC IMAGING OF PROTON-IRRADIATED HIGH Tc SUPERCONDUCTING THIN FILMS: A REVISIT OF Jc(T) FUNCTIONAL AND FLUX PINNING ENHANCEMENT

2001 ◽  
Vol 15 (24n25) ◽  
pp. 3357-3358
Author(s):  
Chong Wang ◽  
Hye-Won Seo ◽  
Chun-Jung Su ◽  
Yuh-Huah Wang ◽  
Q. Y. Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Fields ◽  
External Field ◽  
Critical Current Density ◽  
Current Density ◽  
Flux Pinning ◽  
Ybco Film ◽  
Superconducting Thin Films ◽  
High Tc ◽  
Quantitative Measurements

We have performed systematic quantitative measurements of the critical current density Jc(B, T) for YBCO thin films proton-irradiated to various dosages using the MOI technique. Results for external magnetic fields up to 400Oe and temperature ranging from 5 to 80K are presented for a 600nm thick YBCO film irradiated by proton up to a dosage of 1016 cm -2 at 500 keV. While no significant differences were observed for T>50K, the Jc values consistently increased with the increasing external field for T<50K.

MAGNETIC PROPERTIES OF THE HIGH Tc SUPERCONDUCTORS BiSrCaCuO AND TlBaCaCuO

1989 ◽  
Vol 03 (01) ◽  
pp. 77-85 ◽  
Author(s):  
Y. D. DAI ◽  
C. LIN ◽  
W. B. ZHANG ◽  
S. Q. FENG ◽  
X. ZHU ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Flux Pinning ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
High Tc Superconductors ◽  
Magnetic Current ◽  
High Tc ◽  
Bean Model ◽  
Current Densities ◽  
Magnetic Hysteresis Loops

Magnetic properties of the high T c superconductors BiSrCaCuO and TlBaCaCuO were investigated systematically. Magnetic current densities were calculated from magnetic hysteresis loops of bulk and powdered samples by Bean model. The results showed that flux pinning in these materials is much weaker than that in YBaCuO.

Internal friction in high Tc iron doped 1-2-3 yttrium ceramic superconductors

1990 ◽  
Vol 74 (7) ◽  
pp. 595-598 ◽  
Author(s):  
B. Kusz ◽  
R. Barczynski ◽  
M. Gazda ◽  
L. Murawski ◽  
O. Gzowski ◽  
...  
Keyword(s):  
Internal Friction ◽  
High Tc ◽  
Ceramic Superconductors ◽  
Iron Doped
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