|   | 
Details
   web
Records
Author Esparza, D.A.; D'Ovidio, C.A.; Guimpel, J.; Osquiguil, E.; Civale, L.; de la Cruz, F.
Title The granular nature of bulk superconductivity at 40K in La1.8Sr0.2CuO4 Type Journal Article
Year (up) 1987 Publication Solid State Communications Abbreviated Journal Solid State Commun.
Volume 63 Issue 2 Pages 137-140
Keywords CERAMIC MATERIALS; GRANULAR MATERIALS; LANTHANUM COMPOUNDS – Electric Conductivity; CRITICAL FIELDS; HIGH TEMPERATURE SUPERCONDUCTOR; MAGNETIC FLUX EXPULSION; TEMPERATURE DEPENDENCE; SUPERCONDUCTING MATERIALS
Abstract We have measured the electrical resistivity, magnetic flux expulsion and critical fields of the new high temperature superconductor La1.8Sr0.2CuO4 after different heat treatments. Our data show that the complete flux expulsion in these samples is consistent with the presence of shielding currents induced in multiple connected structures. The magnetization measurements indicate that the lowest field where flux penetrates into the sample should not be taken to be the bulk Hcl. It is shown that the absolute value of the electrical resistivity and its temperature dependence are not correlated with the superconducting critical field and temperature. We discuss the behaviour of the superconducting parameters and their relation with the electrical resistivity.
Address Basic Research Department, Centro At
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 00381098 (ISSN) ISBN Medium
Area Expedition Conference
Notes Export Date: 17 April 2009; Source: Scopus; CODEN: SSCOA; Language of Original Document: English; Correspondence Address: Esparza, D.A.; Applied Research Department; Centro At Approved no
Call Number BT @ osquigui @ Serial 418
Permanent link to this record
 

 
Author Núñez Regueiro, M.; Esquinazi, P.; Izbizky, M.A.; Durán, C.; Castello, D.; Luzuriaga, J.
Title Tunneling systems in high temperature superconductors Type Journal Article
Year (up) 1988 Publication Annales de Physique Abbreviated Journal Ann. Phys. Fr.
Volume 13 Issue 5 Pages 401-406
Keywords acoustic wave absorption; acoustic wave velocity; barium compounds; high temperature superconductors; lanthanum compounds; rare earth compounds; strontium compounds; superconductive tunnelling; thermal conductivity of solids; tunnelling systems; high temperature superconductors; thermal conductivity; sound attenuation; sound velocity; model; low temperature specific heat; La Sr Cu O
Abstract We have measured the thermal conductivity, sound attenuation and relative variation of sound velocity of compounds of the La-Sr-Cu-O and RBa2Cu3O7 families, where R is a rare-earth. We have found that all these properties can be quantitatively correlated within a tunneling system model similar to that used in amorphous materials. This interpretation would naturally explain the anomalous linear term of the low temperature specific heat observed in these materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-4169 ISBN Medium
Area Expedition Conference
Notes ISI:A1988Q715000009 Approved no
Call Number BT @ hernan @ Serial 264
Permanent link to this record
 

 
Author Osquiguil, E.; Decca, R.; Nieva, G.; Civale, L.; de la Cruz, F.
Title La1.80 Sr0.20 CuO4-delta a clean limit superconductor Type Journal Article
Year (up) 1988 Publication Solid State Communications Abbreviated Journal Solid State Commun.
Volume 65 Issue 6 Pages 491-494
Keywords CERAMIC MATERIALS; LANTHANUM COMPOUNDS – Electric Conductivity; CERAMIC SUPERCONDUCTORS; CLEAN LIMIT SUPERCONDUCTOR; HIGH-TEMPERATURE SUPERCONDUCTORS; OXYGEN CONCENTRATION; SUPERCONDUCTING MATERIALS
Abstract The electrical resistivity of the superconductor La1.80Sr0.20Cu04-? has been measured in a wide range of temperatures as a function of oxygen and vacuum heat treatments. The resistivity changes reversibly orders of magnitude with oxygen concentration. There is no sign of saturation at high temperatures, even for samples where the resistivity is increased by heat treatment in vacuum. Using the experimental data and general arguments it is concluded that the ceramic superconductors are high ? materials in the clean limit.
Address Instituto Balseiro 8400 Bariloche, R.N., Argentina# # Comisi
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 00381098 (ISSN) ISBN Medium
Area Expedition Conference
Notes Export Date: 17 April 2009; Source: Scopus; CODEN: SSCOA; Language of Original Document: English; Correspondence Address: Osquiguil, E. Approved no
Call Number BT @ osquigui @ Serial 416
Permanent link to this record
 

 
Author Decca, R.; Osquiguil, E.; de la Cruz, F.; D'Ovidio, C.; Malachevski, M.T.; Esparza, D.
Title Non linear temperature dependence of the resistivity of LaSrCuO: Effects of Sr content Type Journal Article
Year (up) 1989 Publication Solid State Communications Abbreviated Journal Solid State Commun.
Volume 69 Issue 4 Pages 355-357
Keywords Ceramic Materials; Lanthanum Compounds--Electric Conductivity; Superconductivity; Ceramic Superconductors; Superconducting Materials
Abstract The linear temperature dependence of the electrical resistivity has been taken to be one of the characteristic features of the ceramic superconductors. Measurements of the electrical resistance of the LaSrCuO system in a wide temperature range show that the previous statement is only an approximation valid for some values of the Sr concentration.
Address Applied Research Department, Centro At'omico Bariloche
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 00381098 (ISSN) ISBN Medium
Area Expedition Conference
Notes Cited By (since 1996): 2; Export Date: 17 April 2009; Source: Scopus; CODEN: SSCOA; Language of Original Document: English; Correspondence Address: Decca, R.; Basic Research Department; Centro At Approved no
Call Number BT @ osquigui @ Serial 414
Permanent link to this record
 

 
Author Rodriguez, E.; Luzuriaga, J.; Núñez Regueiro, M.; Fainstein, C.
Title Low temperature internal friction peak in high Tc superconductors Type Journal Article
Year (up) 1991 Publication Solid State Communications Abbreviated Journal Solid State Commun.
Volume 77 Issue 10 Pages 777-780
Keywords Ceramic Materials; Oxides – Acoustic Properties; Yttrium Compounds – Acoustic Properties; Acoustic Variables Measurement; Attenuation Peak; Calcium Compounds; Low Temperature Internal Friction Peak; Strontium Compounds; Thermally Activated Relaxation Behavior; High Temperature Superconductors
Abstract We measure the internal friction Q-1 in YBa2Cu3O7-x and Bi2Sr2CaCu2O8+x samples. At temperatures near 35 K for KHz frequencies we observe an attenuation peak. In the case of YBa2Cu3O7-x, assuming a thermally activated relaxation behaviour, we are able to show that it corresponds to the same process as other peaks observed at higher frequencies. For Bi2Sr2CaCu2O8+x this is not the case, and the origin of the peak, found in all the measured samples, remains unknown.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098 ISBN Medium
Area Expedition Conference
Notes ISI:A1991FA71400006 Approved no
Call Number BT @ hernan @ Serial 256
Permanent link to this record
 

 
Author Dhalle, M.; Boon, W.; Osquiguil, E.; Van Haesendonck, C.; Bruynseraede, Y.; Kwarciak, J.; Van Der Biest, O.
Title Correlation between critical current and resistivity in YBa2Cu3O7 Type Journal Article
Year (up) 1991 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 185-189 Issue PART 4 Pages 2447-2448
Keywords Ceramic Materials; Yttrium Compounds--Electric Conductivity; Critical Currents; Oxide Superconductors; Yttrium Barium Copper Oxides; High Temperature Superconductors
Abstract Critical current versus temperature measurements were carried out in ceramic YBa2Cu3O7 samples. The samples were all prepared using the same sintering procedure, but starting from powders obtained by different wet and dry methods. All samples showed a linear Jc vs. T behaviour, typical of Josephson weak-link coupling, with a slope that depends on the preparation method. Using the Ambegaokar-Baratoff relation for Jc, the difference in slopes can be attributed to a change in the characteristic value of the junction resistance. This value turns out to be clearly correlated with the resistivity in the normal state.
Address Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, de Croylaan 2, B-3001 Leuven, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 09214534 (ISSN) ISBN Medium
Area Expedition Conference
Notes Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Dhalle, M.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven; Celestijnenlaan 200D B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 410
Permanent link to this record
 

 
Author Vanacken, J.; Osquiguil, E.; Bruynseraede, Y.
Title Irreversibility line and critical currents in oxygen deficient YBa2Cu3Ox ceramics Type Journal Article
Year (up) 1991 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 183 Issue 1-3 Pages 163-166
Keywords Ceramic Materials; Crystals; Oxygen; Yttrium Compounds; Critical Currents; Oxide Superconductors; Yttrium Barium Copper Oxides; High Temperature Superconductors
Abstract The influence of oxygen concentration on the irreversibility line and critical current of polycrystalline YBa2Cu3Ox was determined using field and zero-field cooled magnetic measurements and magnetic hysteresis data. Although the field dependence of Tirr(H) is unchanged, the irreversibility line shifts to lower temperatures for decreasing oxygen content and the critical current density is strongly reduced.
Address Laboratorium voor Vaste Stof-Fysika en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 09214534 (ISSN) ISBN Medium
Area Expedition Conference
Notes Cited By (since 1996): 8; Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Vanacken, J.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven; Celestijnenlaan 200D 3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 413
Permanent link to this record
 

 
Author Nakamura, O.; Chan, I.; Guimpel, J.; Schuller, I.
Title New buffer layer for high?temperature superconducting ceramics on sapphire: LaBa2Cu3Oy/Ag bilayers Type Journal Article
Year (up) 1991 Publication Applied Physics Letters Abbreviated Journal Appl. Phys. Lett.
Volume 59 Issue 10 Pages 1245
Keywords Superconducting Films; Fabrication; High?Tc Superconductors; Lanthanum Oxides; Barium Oxides; Copper Oxides; Silver; Superconducting Junctions; Superconductivity; Dysprosium Oxides; Sputtering; Sapphire; Crystal Structure; Crystal Growth; Very High Temperature
Abstract
Address
Corporate Author Thesis
Publisher Aip Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ jguimpel @ Serial 611
Permanent link to this record
 

 
Author Vanacken, J.; Libbrecht, S.; Maenhoudt, M.; Van Haesendonck, C.; Osquiguil, E.; Bruynseraede, Y.
Title The magnetic moment relaxation in oxygen-deficient YBa2Cu3Ox Type Journal Article
Year (up) 1992 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 197 Issue 1-2 Pages 9-14
Keywords Magnetic Measurements – Relaxation; Oxygen – Concentration; Relaxation Processes – High Temperature Effects; Relaxation Processes – Magnetic Field Effects; Magnetic Moment Relaxation; Oxygen Deficiency; Yttrium Barium Copper Oxides; High Temperature Superconductors
Abstract The magnetic moment relaxation in polycrystalline YBa2Cu3Oxmaterial has been studied using zero-field-cooled measurements. The temperature dependence of the relaxation rate shows a field-dependent maximum. When the oxygen content is reduced, the maximum shifts towards lower temperatures. This shift is directly related to a decrease of the intragrain critical current density in the oxygen-deficient material, inducing a decrease of the field H* for complete flux penetration. The characteristic activation energies for depinning in the oxygen-deficient material are below 20 meV.
Address Laboratorium voor Vaste Stof-Fysika en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 09214534 (ISSN) ISBN Medium
Area Expedition Conference
Notes Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Vanacken, J.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven; Celestijnenlaan 200 D B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 409
Permanent link to this record
 

 
Author Luzuriaga, J.; Andre, M.-O.; Benoit, W.
Title Frequency and amplitude response of the flux-line lattice to mechanical perturbation in ceramic YBa2Cu3O7 Type Journal Article
Year (up) 1992 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 201 Issue 3-4 Pages 257-262
Keywords Copper oxides; Crystal lattices; Frequency response; Internal friction; Lattice vibrations; Magnetic fields; Mathematical models; Mechanical properties; Pendulums; Rheology; Thermal effects; Torque; Yttrium compounds; Amplitude response; Ceramic yttrium barium copper oxides; Extended dry friction model; Flux line lattices; Forced pendulum; Frequency independent dissipation peak; Mechanical response; Thermal activation; High temperature superconductors
Abstract The mechanical response of the flux-line lattice has been measured with a low-frequency forced pendulum in ceramic YBa2Cu3O7. A dissipation peak observed in temperature sweeps is frequency-independent between 1 mHz and 5 Hz. Dissipation depends strongly on applied torque, and for fixed temperatures this dependence is well fitted by a rheological model of extended dry friction. If the model is extended to take account of thermal activation, however, it does not agree with the measured frequency independence, which is hard to explain within simple models of thermal activation.
Address Institut de G
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 09214534 (ISSN) ISBN Medium
Area Expedition Conference
Notes Export Date: 28 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Luzuriaga, J.; Institut de G Approved no
Call Number BT @ luzuriag @ Serial 487
Permanent link to this record