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Author Watt
Title Photoinduced changes in Raman spectra of YBa2Cu3O6.4 films Type Journal Article
Year 1994 Publication Journal of Superconductivity Abbreviated Journal J Supercond
Volume 7 Issue (up) 1 Pages 131-136
Keywords Electronic Raman scattering; oxygen ordering; photoinduced superconductivity; two-magnon scattering; Copper oxides; Radiation effects; Raman spectroscopy; Superconducting films; Superconductivity; Oxide superconductors; Photoinduced effects; Yttrium barium cuprates; High temperature superconductors
Abstract The evolution of Raman spectra with illumination has been studied in YBa2Cu3O6.4 films at temperatures between 5-300 K. Low laser power has always been used to avoid local overheating, which was controlled by measuring the local temperature by the Stokes/anti-Stokes ratio. Three important photoinduced effects have been found: (i) the enhancement of the intensity of the observed phonon modes: (Cu(2) at 141 cm-1, O(2)-O(3) at 338 cm-1, and O(4) at 488 cm-1), which may be related to the ordering of oxygen vacancies, (ii) the increase of the electronic scattering background for low Raman frequencies ?, which is in agreement with the enhancement of the static conductivity ?(??0) after illumination, and (iii) the suppression of the intensity of the two-magnon band, which may be caused by the increase of charge carriers due to photodoping.
Address Laboratorium voor Vaste Stof-Fysika en Magnetisme, KU Leuven, Leuven, B-3001, Belgium
Corporate Author Thesis
Publisher Kluwer Academic Publishers-Plenum Publishers Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 08961107 (ISSN) ISBN Medium
Area Expedition Conference
Notes Cited By (since 1996): 11; Export Date: 17 April 2009; Source: Scopus; CODEN: JOUSE; doi: 10.1007/BF00730383; Language of Original Document: English; Correspondence Address: Watt Approved no
Call Number BT @ osquigui @ Serial 396
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Author Libbrecht, S.; Osquiguil, E.; Wuyts, B.; Maenhoudt, M.; Gao, Z.X.; Bruynseraede, Y.
Title Effect of room temperature annealing on the properties of oxygen- deficient YBa2Cu3Ox films Type Journal Article
Year 1993 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 206 Issue (up) 1-2 Pages 51-58
Keywords Annealing; Ceramic materials; Hall effect; Superconducting films; Yttrium compounds; Critical current density; Oxide superconductors; Yttrium barium copper oxides; High temperature superconductors
Abstract Annealing at room temperature of quenched oxygen-depleted YBa2Cu3Oxn (6.5?xn<6.8) films, produces a clear increase in the critical temperature Tc and current density Jc, while the normal state resistivity ?{variant}xx and Hall coefficient RH decrease as a function of annealing time, indicating an increase in carrier density. The enhancement of the critical current density Jc is more pronounced at high fields and temperatures due to a shift of the irreversibility line, which scales with the increasing Tc. The observed changes are accompanied by corresponding changes in the crystalline structure, which can be related to oxygen ordering effects.
Address Laboratorium voor Vaste Stof-Fysika en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 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 Cited By (since 1996): 11; Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Libbrecht, S.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven; Celestijnenlaan 200D B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 402
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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 1991 Publication Applied Physics Letters Abbreviated Journal Appl. Phys. Lett.
Volume 59 Issue (up) 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
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ jguimpel @ Serial 611
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Author Libbrecht, S.; Osquiguil, E.; Bruynseraede, Y.
Title Influence of field inhomogeneity on the magnetization of YBCO films Type Journal Article
Year 1994 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 225 Issue (up) 3-4 Pages 337-345
Keywords Magnetization; Superconducting films; SQUID magnetometers; Superconducting ceramics; YBCO superconductors; High temperature superconductors
Abstract DC magnetization data of superconducting thin YBCO films, measured by means of a magnetometer in which the sample is pulled through a set of pick-up coils, are often calculated from pick-up signals which clearly deviate from the ideal response. We show how these signal distortions influence the values obtained for the magnetization, and present a simple model that enables one to simulate the temperature dependence of these distorted pick-up signals, in the case of low-field magnetization measurements. The model is based on the magnetic field inhomogeneity of the magnetometer, in combination with the hysteretic magnetization of the superconducting sample. Optimum values for the model parameters are derived and discussed.
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 Cited By (since 1996): 11; Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Bruynseraede, Y.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven; Celestijnenlaan 200 D B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 394
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Author Wuyts, B.; Osquiguil, E.; Maenhoudt, M.; Libbrecht, S.; Gao, Z.X.; Bruynseraede, Y.
Title Relation between the Hall angle slope and the carrier density in oxygen-depleted YBa2Cu3Ox films Type Journal Article
Year 1994 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 222 Issue (up) 3-4 Pages 341-348
Keywords Doping (additives); Electric conductivity; Hall effect; Mathematical models; Thermal effects; Thin films; Transport properties; Yttrium compounds; Carrier density; Hall angle slope; Oxygen content; Zero temperature intercept; Superconducting films
Abstract A detailed study of the Hall angle cot?H in YBa2Cu3Ox epitaxial thin films with various oxygen contents clearly shows the existence of a linear relation between the slope of cot?H versus T2 and the carrier density. The zero-temperature intercept C=cot?H(T=0 K) and the mobility at room temperature change substantially for an oxygen content x?6.6, indicating that both effects are closely related.
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 Cited By (since 1996): 8; Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Bruynseraede, Y.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven; Celestijnenlaan 200 D B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 395
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Author Wuyts, B.; Gao, Z.X.; Libbrecht, S.; Maenhoudt, M.; Osquiguil, E.; Bruynseraede, Y.
Title Growth of particle-free YBa2Cu3O7 films by off-axis sputtering Type Journal Article
Year 1992 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 203 Issue (up) 3-4 Pages 235-239
Keywords Copper oxides; Film growth; Film preparation; Magnetrons; Particles (particulate matter); Sputter deposition; Substrates; Superconductivity; Thin films; Yttrium compounds; Critical current density; Off axis single target magnetron sputtering; Particle free superconducting films; Yttrium barium copper oxides; Superconducting films
Abstract The preparation of good YBa2Cu3O7 thin films is often hindered by the production of non-stoichiometric particles which degrade the superconducting properties of the layer. A systematic study of films prepared by off-axis single target magnetron sputtering shows that the presence of copper-rich particles dramatically decreases the critical current density but does not affect the critical temperature. The formation of these particles can be avoided by carefully adjusting the position of the substrate with respect to the target. Films without off-stoichiometric particles have excellent superconducting properties.
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 Cited By (since 1996): 10; Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Wuyts, B.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven; Celestijnenlaan 200 D B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 403
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Author Osquiguil, E.; Maenhoudt, M.; Wuyts, B.; Bruynseraede, Y.; Lederman, D.; Nieva, G.; Guimpel, J.; Schuller, I.K.
Title Photoexcitation effects in YBa2Cu3Ox Type Journal Article
Year 1993 Publication Journal of Alloys and Compounds Abbreviated Journal J Alloys Compd
Volume 195 Issue (up) C Pages 667-670
Keywords Barium compounds; Ceramic materials; Copper oxides; High temperature superconductors; Oxides; Photoelectricity; Yttrium compounds; C-axis oriented films; Photoexcitation effects; Photoinduced phenomena; Yttrium barium cuprates; Superconducting films
Abstract We show through photoexcitation experiments carried out on YBa2Cu3Ox c-axis oriented films that photoinduced phenomena are not restricted to insulating samples. Superconducting films with critical temperatures varying between 2 K and 40 K show a clear enhancement of the superconducting transition after illumination. The increase in Tc is accompanied by a corresponding decrease in the resistivity ?, and an increase in the Hall coefficient RH, indicative of an increased carrier density. Furthermore, the carrier mobility is also affected by illumination.
Address Physics Department – 0319, University of California – San Diego, La Jolla, CA 92093-0319, United States
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 09258388 (ISSN) ISBN Medium
Area Expedition Conference
Notes Cited By (since 1996): 4; Export Date: 17 April 2009; Source: Scopus; CODEN: JALCE; Language of Original Document: English; Correspondence Address: Osquiguil, E.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; Katholieke Universiteit Leuven B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 401
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Author Neerinck, D.; Temst, K.; Baert, M.; Osquiguil, E.; Van Haesendonck, C.; Bruynseraede, Y.; Gilabert, A.; Schuller, I.K.
Title Thermally induced transition in the vortex lattice of Ge/Pb multilayers Type Journal Article
Year 1991 Publication Physica C: Superconductivity and its applications Abbreviated Journal Phys C Supercond Appl
Volume 185-189 Issue (up) PART 3 Pages 2061-2062
Keywords Germanium And Alloys; Lead And Alloys; Superconducting Films; Thermal Effects; Critical Currents; Multilayers; Metallic Films
Abstract We report on a novel magnetic field dependence of the critical current density of M.B.E. grown Ge/Pb insulator/superconductor multilayers. When the magnetic field is applied perpendicular to the layers, the critical current density Jc drops to a minimum, followed by a broad maximum before finally decaying monotonously to zezero with increasing magnetic field. The dependence of this effect on pinning strength, temperature, and layer thickness suggests either a thermally driven coupling/decoupling transition, or melting of the vortex lattice.
Address Physics Department, University of California, San Diego, CA 92093-0319, United States
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: Neerinck, D.; Laboratorium voor Vaste Stof-Fysika en Magnetisme; K.U. Leuven B-3001 Leuven, Belgium Approved no
Call Number BT @ osquigui @ Serial 412
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