| Records |
| Author |
Pedrazzini, P.; Jaccard, D.; Lapertot, G.; Flouquet, J.; Inada, Y.; Kohara, H.; Onuki, Y. |
| Title |
Probing the extended non-Fermi liquid regimes of MnSi and Fe |
Type |
Journal Article |
| Year |
2006 |
Publication  |
Physica B – Condensed Matter |
Abbreviated Journal |
Physica B |
| Volume |
378-380 |
Issue |
|
Pages |
165-166 |
| Keywords |
electrical resistivity; Fermi liquid; ferromagnetic materials; high-pressure effects; iron; magnetic superconductors; manganese alloys; silicon alloys; strongly correlated electron systems; superconducting transition temperature; superconducting transitions; whiskers; MnSi; Fe |
| Abstract |
Recent studies show that the non-Fermi liquid (NFL) behavior of MnSi and Fe spans over an unexpectedly broad pressure range, between the critical pressure p and around 2p. In order to determine the extension of their NFL regions, we analyze the evolution of the resistivity ρ(T)˜A(p)T at higher pressures. We find that in MnSi the n=32 exponent holds below 4.8GPa≈3p, but it increases above that pressure. At 7.2 GPa we observe the low-temperature Fermi liquid exponent n=2 whereas for T>1.5K, n=53. Our measurements in Fe show that the NFL behavior ρ˜T extends at least up to 30.5 GPa, above the entire superconducting (SC) region. In the studied pressure range, the onset of the SC transition reduces by a factor 10 down to Tconset(30.5GPa)=0.23K, while the A—coefficient diminishes monotonically by around 50%. |
| 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 |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
BT @ pedrazp @ |
Serial |
469 |
| Permanent link to this record |
| |
|
| |
| Author |
Fasano, Y.; Szabó, P.; KaÄmarÄík, J.; Pribulová, Z.; Pedrazzini, P.; Samuely, P.; Correa, V.F. |
| Title |
Unconventional superconductivity in the strong-coupling limit for the heavy fermion system CeCoIn5 |
Type |
Journal Article |
| Year |
2018 |
Publication |
Physica B: Condensed Matter |
Abbreviated Journal |
Physica B |
| Volume |
536 |
Issue |
|
Pages |
798-802 |
| Keywords |
Heavy fermion superconductors; Scanning tunneling spectroscopy; Superconducting phase; Pseudogap phase |
| Abstract |
We present scanning tunneling spectroscopy measurements of the local quasiparticles' excitation spectra of the heavy fermion CeCoIn5 between 440mK and 3K in samples with a bulk Tc=2.25K. The spectral shape of our low-temperature tunneling data, quite textbook nodal-Δ conductance, allow us to confidently fit the spectra with a d-wave density of states considering also a shortening of quasiparticles' lifetime term Γ. The Δ(0) value obtained from the fits yields a BCS ratio 2Δ/kTc=7.73 suggesting that CeCoIn5 is an unconventional superconductor in the strong coupling limit. The fits also reveal that the height of coherence peaks in CeCoIn5 is reduced with respect to a pure BCS spectra and therefore the coupling of quasiparticles with spin excitations should play a relevant role. The tunneling conductance shows a depletion at energies smaller than Δ for temperatures larger than the bulk Tc, giving further support to the existence of a pseudogap phase that in our samples span up to T*∼1.2Tc. The phenomenological scaling of the pseudogap temperature observed in various families of cuprates, 2Δ/kT*∼4.3, is not fulfilled in our measurements. This suggests that in CeCoIn5 the strong magnetic fluctuations might conspire to close the local superconducting gap at a smaller pesudogap temperature-scale than in cuprates. |
| 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 |
0921-4526 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
BT @ pedrazp @ |
Serial |
766 |
| Permanent link to this record |
| |
|
| |
| Author |
Herbsommer, J.A.; Luzuriaga, J.; Cheong, S.-W. |
| Title |
Vortex glass melting in single crystal La1.825 Sr0.075CuO4 |
Type |
Journal Article |
| Year |
1996 |
Publication |
Physica C |
Abbreviated Journal |
Physica C |
| Volume |
258 |
Issue |
1-2 |
Pages |
169-174 |
| Keywords |
Copper compounds; Crystal lattices; Frequency response; Glass; Magnetic field measurement; Magnetic permeability measurement; Melting; Phase diagrams; Single crystals; Temperature; Vortex flow; AC susceptibility; Cuprates; Pinned flux lattice; Oxide superconductors |
| Abstract |
The vortex phase diagram in single crystalline La1.85Sr0.075CuO4 has been studied using an AC-susceptibility technique. A peak in the out-of-phase (x?) component of the susceptibility indicates a transition from a pinned flux lattice (FLL) to an unpinned one. This peak is frequency dependent for all the values of the magnetic field measured (0.01 to 4 T), and this, as well as the general behavior found in the cuprates, has prompted us to interpret our data as evidence for a vortex-glass to liquid transition in the FLL. The activation energies obtained can be fitted to a theory developed by Vinokur et al. Measurements with the magnetic field at an angle with the Cu-O planes may also be understood qualitatively within this framework. |
| Address |
AT and T Bell Laboratories, Murray Hill, NJ, 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 |
Cited By (since 1996): 2; Export Date: 28 April 2009; Source: Scopus; CODEN: PHYCE; doi: 10.1016/0921-4534(95)00812-8; Language of Original Document: English; Correspondence Address: Luzuriaga, J.; Centro At |
Approved |
no |
| Call Number |
BT @ luzuriag @ |
Serial |
483 |
| Permanent link to this record |
| |
|
| |
| Author |
L |
| Title |
Dynamic softening of vortex lines in YBa2Cu3O7-? single crystals |
Type |
Journal Article |
| Year |
1996 |
Publication |
Physica C: Superconductivity and its Applications |
Abbreviated Journal |
Phys C Supercond Appl |
| Volume |
260 |
Issue |
3-4 |
Pages |
211-216 |
| Keywords |
Crystal defects; Magnetic anisotropy; Magnetic couplings; Mathematical models; Single crystals; Transport properties; Vortex flow; Yttrium compounds; Dynamic softening; Flux transformer configuration; Pinning potential; Transport measurements; Vortex correlation; Vortex line; Yttrium barium cuprates; High temperature superconductors |
| Abstract |
Transport measurements in the mixed state of oxygen-deficient YBa2Cu3O7-? single crystals using the flux transformer configuration show that the flux liquid changes with increasing anisotropy from strongly correlated to uncorrelated in the field direction. For intermediate coupling, the current inducing loss of vortex correlation has a maximum near the irreversibility temperature. Thus, an effective softening of vortex lines with decreasing temperature is detected. We propose a simple model that accounts for this behavior by including the effects of the pinning potential on the dynamics of vortices. |
| Address |
Comn. Nac. de Ener. 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 |
09214534 (ISSN) |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
Cited By (since 1996): 4; Export Date: 17 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Righi, E.F.; Comn. Nac. de Ener. At |
Approved |
no |
| Call Number |
BT @ osquigui @ |
Serial |
384 |
| Permanent link to this record |
| |
|
| |
| 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 |
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 |
| Permanent link to this record |
| |
|
| |
| 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 |
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 |
| 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 |
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 |
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 |
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 |
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 |
Rodr |
| Title |
Role of anisotropy in the vortex lattice of superconductors high-Q oscillator measurements in 2H-NbSe2 and La1.825Sr0.075CuO4 |
Type |
Journal Article |
| Year |
1994 |
Publication |
Physica C: Superconductivity and its applications |
Abbreviated Journal |
Phys C Supercond Appl |
| Volume |
229 |
Issue |
1-2 |
Pages |
59-64 |
| Keywords |
Anisotropy; Copper oxides; High temperature superconductors; Lanthanum compounds; Magnetic field effects; Niobium compounds; Oscillators (mechanical); Phase transitions; Superconductivity; Thickness measurement; Angular dependence; Ginzburg Landau theory; Pinning; Crystal lattices |
| Abstract |
Measurement of the response of the flux-line lattice in NbSe2 and La1.825Sr0.075CuO4 show important differences between these two materials. In particular, we have studied the magnetic-field and angular dependence of the response of a high-Q mechanical oscillator in fields of up to 1 T. The features seen in NbSe2 seem to be well explained in terms of a change in the pinning regime, usually termed the “peak effect” in the critical current, using the collective-pinning model of Larkin and Ovchivnikov within Ginzburg-Landau anisotropic theory. On the other hand the behavior found in the high-Tc material LSCO seems to fall naturally into a description which takes into account the possibility of phase transitions in the vortex lattice and the quasi-two-dimensional character of the superconductivity. |
| Address |
AT and T Bell Laboratories, Murray hill, NJ 07974, USA |
| 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): 2; Export Date: 28 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Luzuriaga, J.; Comisi |
Approved |
no |
| Call Number |
BT @ luzuriag @ |
Serial |
484 |
| Permanent link to this record |
