| Records |
| Author |
Monton, C.; de la Cruz, F.; Guimpel, J. |
| Title |
Magnetic state modification induced by superconducting response in ferromagnet/superconductor Nb/Co superlattices |
Type |
Journal Article |
| Year |
2008 |
Publication |
PHYSICAL REVIEW B |
Abbreviated Journal |
|
| Volume |
77 |
Issue |
10 |
Pages |
|
| Keywords |
|
| Abstract |
Magnetization measurements in superconductor/ferromagnet Nb/Co superlattices show a complex behavior as a function of temperature, applied field, and sample history. Based on a simple model, it is shown that this behavior is due to an interplay between the superconductor magnetization temperature dependence, the ferromagnet magnetization time dependence, and the stray fields of both materials. It is also shown that the magnetic state of the Co layers is modified by the Nb superconducting response, implying that the problem of a superconductor/ferromagnetic heterogeneous sample has to be solved in a self-consistent manner. |
| 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 |
1098-0121 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
Notes  |
ISI:000254542700117 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
146 |
| Permanent link to this record |
| |
|
| |
| Author |
Bridoux, G.; Nieva, G.; de la Cruz, F. |
| Title |
Phase-coherence effects in vortex transport entropy |
Type |
Journal Article |
| Year |
2008 |
Publication |
PHYSICAL REVIEW LETTERS |
Abbreviated Journal |
|
| Volume |
101 |
Issue |
11 |
Pages |
117002 |
| Keywords |
|
| Abstract |
Nernst and electrical resistivity measurements in superconducting YBa2Cu3O7-delta and Bi2Sr2CaCu2O8+delta with and without columnar defects show a distinctive thermodynamics of the respective liquid vortex matter. At a field-dependent high temperature region in the H-T phase diagram, the Nernst signal is independent of structural defects in both materials. At lower temperatures, in YBa2Cu3O7-delta, defects contribute only to the vortex mobility, and the transport entropy is that of a system of vortex lines. The transition to lower temperatures in Bi2Sr2CaCu2O8+delta has a different origin; the maximum in the Nernst signal when decreasing temperature is not associated with transport properties but with the entropy behavior of pancake vortices in the presence of structural defects. |
| 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 |
0031-9007 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
ISI:000259188700052 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
195 |
| Permanent link to this record |
| |
|
| |
| Author |
de la Cruz, F.; Fink, H.J.; Luzuriaga, J. |
| Title |
Temperature dependence of the superconducting giant-vortex state. Theory and Experiment |
Type |
Journal Article |
| Year |
1979 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys. Rev. B |
| Volume |
20 |
Issue |
5 |
Pages |
1947-1959 |
| Keywords |
|
| Abstract |
When a type-I superconductor with a surface nucleation field Hc3(T)>Hc(T) (thermodynamic critical field) is thermally cycled in an axially applied magnetic field H0 between the temperatures T(Hc3) and about T(Hc), experiments show that the magnetization changes reversibly. The latter is diamagnetic near T(Hc3) but can be paramagnetic just above T(Hc). This behavior is explained by assuming that the fluxoid quantum number b is fixed at the transition from the normal to the superconducting state and retained at lower temperatures. The value of b is determined almost entirely by the flux at the transition which is enclosed by a contour located at a distance ξ1.7 from the surface inside the cylinder (ξ is the coherence length). The temperature variation of the order parameter f at the surface of the cylinder, the magnetization m, and the temperature at which m=0 for f≠0 are calculated for R>>ξ. Conservation of the fluxoid quantum number, while T is varied causes the two opposing surface currents to become imbalanced. This is the source of the observed para- and diamagnetism. |
| 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 |
0163-1829 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
ISI:A1979HP51300019 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
275 |
| Permanent link to this record |
| |
|
| |
| Author |
Guimpel, J.; de la Cruz, M.E.; de la Cruz, F.; Fink, H.J.; Laborde, O.; Villegier, J.C. |
| Title |
Size dependence of the Superconducting critical temperature and fields of Nb/Al multilayers |
Type |
Journal Article |
| Year |
1986 |
Publication |
Journal of Low Temperature Physics |
Abbreviated Journal |
J. Low Temp. Phys. |
| Volume |
63 |
Issue |
1-2 |
Pages |
151-165 |
| Keywords |
|
| Abstract |
The critical temperatureT cof Nb/Al multilayers decreases as the total sample thicknessd Tis decreased while the thickness of each Nb and Al layer is kept constant. To understand this behavior, models based on the proximity effect and on weak two-dimensional (2D) localization are employed. The latter uses a characteristic length, the thermal diffusion length, in relation tod Tto obtain 2D behavior and leads to a reasonable explanation ofT c(d T). It is also found that the slope atT c(d T) of the critical magnetic field perpendicular to the layers is independent ofd Twhen the Nb and Al layer thicknesses are kept constant. The angular dependence of the critical field is also measured. |
| 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 |
0022-2291 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
ISI:A1986C112200008 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
193 |
| Permanent link to this record |
| |
|
| |
| Author |
Rodríguez, E.; Duran, C.; Luzuriaga, J.; de la Cruz, F.; Fainstein, C. |
| Title |
Anomalous behaviour of the vortex structure in Bi4Ca2Sr4Cu4O16+y measured with a vibrating reed at low magnetic fields |
Type |
Journal Article |
| Year |
1990 |
Publication |
Physica C: Superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
165 |
Issue |
3-4 |
Pages |
315-320 |
| Keywords |
|
| Abstract |
The response of the vortex structure in ceramic samples of Bi4Ca2Sr4Cu4O16+y has been measured by means of a vibrating reed technique in magnetic fields below 0.2 T. An anomally in the response of the reed is seen at temperatures of around 30 to 40 K, well below the critical temperature, indicating a transition similar to that attributed to a melting of the Flux Line Lattice. There is a shift in the temperature at which the anomaly is detected when one increases the driving force on the reed, while the dissipation shows a maximum associated to the transition which scales with the square of the applied magnetic field. Comparison with magnetization measurements shows that there is non-zero critical current at the same temperature where the anomalous behaviour is detected with our technique. |
| 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 |
0921-4534 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
ISI:A1990CN49800014 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
261 |
| Permanent link to this record |
| |
|
| |
| Author |
Arce, R.; de la Cruz, F.; Esquinazi, P. |
| Title |
Superconducting penetration depth in amorphous La70Cu30 |
Type |
Journal Article |
| Year |
1981 |
Publication |
Physica B+C |
Abbreviated Journal |
|
| Volume |
108B |
Issue |
|
Pages |
1253-1254 |
| Keywords |
|
| Abstract |
It is shown that weak field penetration depth measurements can be used to determine the change in the normal and superconducting behaviour of amorphous samples, when heat-treated below the crystallization temperature. The results are used to discuss the validity of BCS-Gorkov relations, when applied to 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 |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
Proceedings of LT-16 |
Approved |
no |
| Call Number |
BT @ pedrazp @ |
Serial |
558 |
| Permanent link to this record |
| |
|
| |
| Author |
Duran, C.; Yazyi, J.; de la Cruz, F.; Bishop, D.J.; Mitzi, D.B.; Kapitulnik, A. |
| Title |
Flux-lattice melting, anisotropy, and the role of interlayer coupling in Bi-Sr-Ca-Cu-O single crystals |
Type |
Journal Article |
| Year |
1991 |
Publication |
Physical Review B |
Abbreviated Journal |
PRB |
| Volume |
44 |
Issue |
14 |
Pages |
7737-7740 |
| Keywords |
|
| Abstract |
We have used the high-Q mechanical-oscillator technique to probe the vortex-lattice structure in high-quality Bi-Sr-Ca-Cu-O single crystals over a wide range of magnetic fields (200 Oe to 40 kOe), and relative orientations θ between the magnetic field and the crystalline c^ axis. In addition to the large softening and dissipation peak previously observed and interpreted as due to flux-lattice melting, another distinctly different peak at higher temperatures is seen. The temperatures where the dissipation peaks take place are solely defined by the parallel component of the field cosθ, while the restoring force on the oscillator is due to both field components. We suggest that the two peaks are due to the softening of interplanar coupling at the low-temperature peak, and melting or depinning of the two-dimensional pancake vortices at the higher-temperature peak. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Physical Society |
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 |
Rapid Communication |
Approved |
no |
| Call Number |
BT @ pedrazp @ 10.1103/PhysRevB.44.7737 |
Serial |
543 |
| Permanent link to this record |
| |
|
| |
| Author |
Guimpel, J.; de la Cruz, F.; Murduck, J.; Schuller, I.K. |
| Title |
Penetration depth of a superconducting superlattice |
Type |
Journal Article |
| Year |
1987 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys. Rev. B |
| Volume |
35 |
Issue |
7 |
Pages |
3655-3656 |
| Keywords |
|
| Abstract |
We have measured the magnetic-flux expulsion of a superconducting superlattice and related it to the Meissner penetration depth. The temperature dependence of the penetration depth is in quantitative agreement with theoretical expectation based on mean-field theory. The zero-temperature penetration depth is found in excellent, quantitative agreement without adjustable parameters with theoretical predictions for dirty superconductors. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Physical Society |
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 |
Rapid Communications |
Approved |
no |
| Call Number |
BT @ pedrazp @ 10.1103/PhysRevB.35.3655 |
Serial |
538 |
| Permanent link to this record |
