| Records |
| Author |
Herbsommer, Juan A. |
| Title |
Dinámica y estática de vórtices en superconductores de alta temperatura crítica con defectos correlacionados |
Type |
Book Whole |
| Year |
2000 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
|
Abstract  |
|
| Address |
Instituto Balseiro |
| Corporate Author |
|
Thesis |
Ph.D. 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 @ hernan @ |
Serial |
328 |
| Permanent link to this record |
| |
|
| |
| Author |
Luzuriaga, J. |
| Title |
Sphere on a vibrating reed for measurements of turbulence in superfluid helium |
Type |
Journal Article |
| Year |
2000 |
Publication |
Journal of Alloys and Compounds |
Abbreviated Journal |
J Alloys Compd |
| Volume |
|
Issue |
|
Pages |
265-268 |
| Keywords |
Cantilever beams; Computational methods; Laminar flow; Oscillators (electronic); Phase transitions; Turbulent flow; Vibrations (mechanical); Oscillating spheres; Spherical geometries; Vibrating reeds; Superfluid helium |
| Abstract |
A modification of the vibrating reed, in which a massive sphere is made to oscillate at the end of a cantilevered beam, has been used for measurements in superfluid helium. The apparatus operates in the same way as a conventional vibrating reed with capacitive detection and drive. However, when operating submerged in the liquid, the frequency changes give information on the superfluid fraction, and the dissipation can be used to obtain information on the change of liquid flow, from laminar to turbulent. The spherical geometry allows an exact calculation of all parameters in the laminar regime, so departures due to the turbulence can be better quantified. The method has been found to work well in practice, and some measurements on the turbulent regime in the superfluid are presented. |
| Address |
Centro At |
| Corporate Author |
|
Thesis |
|
| Publisher |
Elsevier Sequoia SA |
Place of Publication |
Buenos Aires, Argent |
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
12th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS-12) |
Abbreviated Series Title |
|
| Series Volume |
310 |
Series Issue |
1-2 |
Edition |
|
| ISSN |
09258388 (ISSN) |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
Conference code: 57483; Export Date: 28 April 2009; Source: Scopus; CODEN: JALCE; doi: 10.1016/S0925-8388(00)00962-2; Language of Original Document: English; Correspondence Address: Luzuriaga, Javier; Centro Atomico Bariloche Bariloche, Argentina; Sponsors: ABDUS SALAM International Centre for Theoretical Physics; Centre for Industrial Research (CINI); Comision Nacional de Actividades Espaciales (CONAE) |
Approved |
no |
| Call Number |
BT @ luzuriag @ |
Serial |
478 |
| Permanent link to this record |
| |
|
| |
| Author |
Herbsommer, J.A.; Nieva, G.; Luzuriaga, J. |
| Title |
Reproducibility of the disordered vortex structure in twinned single crystals of YBCO |
Type |
Journal Article |
| Year |
2000 |
Publication |
Physica C |
Abbreviated Journal |
Physica C |
| Volume |
341 |
Issue |
|
Pages |
1087-1088 |
| Keywords |
|
| Abstract |
Bitter decorations of the vortices in twinned single crystal YBCO have been obtained to study the disordered structure formed on successive cooldowns of the sample under the same conditions of field and temperature. Between succesive decorations, the iron dots could be removed completely, giving a surface clean enough for further decoration. It was found that successive realizations of the disordered vortex state were very similar at long range, and differed mostly on short scales, compared to the average vortex separation. We have quantified the correlation between successive structures, and double sided decorations have been also performed to compare with the extent of spatial correlation in the applied field direction. The coincidence of the position of the vortices in successive realizations of the structure, is unexpected, and indicates an unusual behavior for a glassy system. Our technique makes it possible to image the position of the vortices in detail and repeatedly, providing us with a model amorphous system in which to study the reproducibility of the disordered structure. |
| 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:000165855700143 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
220 |
| Permanent link to this record |
| |
|
| |
| Author |
Decca, R.S.; Drew, H.D.; Osquiguil, E.; Maiorov, B.; Guimpel, J. |
| Title |
Anomalous proximity effect in underdoped YBa2Cu3O6+x Josephson junctions |
Type |
Journal Article |
| Year |
2000 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
85 |
Issue |
17 |
Pages |
3708-3711 |
| Keywords |
Critical currents; Energy gap; High temperature superconductors; Magnetic field effects; Magnetron sputtering; Mathematical models; Phase diagrams; Phase transitions; Physical properties; Scanning electron microscopy; Superconductivity; Yttrium barium copper oxides; Anomalous proximity effect; Fluctuating phase models; Josephson effect; Photodoping; Josephson junction devices |
| Abstract |
Experiments were carried out to probe the underdoped insulating material by the Josephson effect. Junctions were fabricated by exploiting the capability of locally photodoping insulating RBa2Cu3O6+x (R = rare earth) material. The existence of an anomalously large proximity effect was confirmed. The critical current of the junctions was consisted with the conventional Josephson relationship. |
| Address |
Centro At |
| Corporate Author |
|
Thesis |
|
| Publisher |
American Inst of Physics |
Place of Publication |
Woodbury, NY, United States |
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
00319007 (ISSN) |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
Cited By (since 1996): 36; Export Date: 17 April 2009; Source: Scopus; CODEN: PRLTA; doi: 10.1103/PhysRevLett.85.3708; Language of Original Document: English; Correspondence Address: Decca, R.S.; Univ of Maryland College Park, United States; References: Ginsberg, D.M., (1996) Physical Properties of High Temperature Superconductors V, , World Scientific, Singapore; Zhang, S.C., (1997) Science, 275, p. 1089; Emery, V.J., Kivelson, S.A., (1995) Nature (London), 374, p. 434; Corson, J., (1999) Nature (London), 398, p. 291; Renner, Ch., (1998) Phys. Rev. Lett., 80, p. 149; Demler, E., (1998) Phys. Rev. Lett., 80, p. 2917; Den Hertog, B.C., Berlinsky, A.J., Kallin, C., (1999) Phys. Rev. B, 59, pp. R11645; Emery, V.J., Kivelson, S.A., Zachar, O., (1997) Phys Rev. B, 56, p. 6120; Tinkham, M., (1996) Introduction to Superconductivity, , McGraw-Hill, New York; Decca, R.S., (1998) Appl. Phys. Lett., 73, p. 120; (1999) J. Microsc., 194, p. 407; Osquiguil, E., (1992) Appl. Phys. Lett., 60, p. 1627; Kudinov, V.I., (1993) Phys. Rev. B, 47, p. 9017; Decca, R.S., Drew, H.D., Empson, K.L., (1997) Appl. Phys. Lett., 70, p. 1932; Orenstein, J., (1990) Phys. Rev. B, 42, p. 6342; Nieva, G., (1992) Appl. Phys. Lett., 60, p. 2159; (1992) Phys. Rev. B, 46, p. 14249; notenoteGray, K.E., (1992) Phys. Rev. B, 45, p. 10071; Pauza, A.J., (1997) J. Appl. Phys., 82, p. 5612; Katz, A.S., Woods, S.I., Dynes, R.C., (2000) J. Appl. Phys., 87, p. 2978; noteUR – http://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-19244384844&partnerID=40 |
Approved |
no |
| Call Number |
BT @ osquigui @ |
Serial |
373 |
| Permanent link to this record |
| |
|
| |
| Author |
Pedrazzini, P.; Schmerber, G.; Berisso, M.G.; Kappler, J.P.; Sereni, J.G. |
| Title |
Magnetic and superconducting properties of A(7)B(3) compounds (A = Th or La and B=Ni, Co, Fe or Pd, Rh, Ru) |
Type |
Journal Article |
| Year |
2000 |
Publication |
PHYSICA C |
Abbreviated Journal |
|
| Volume |
336 |
Issue |
1-2 |
Pages |
10-18 |
| Keywords |
|
| Abstract |
High-temperature magnetization, low temperature specific heat, and ac-susceptibility measurements on Th7X3 (X = Ni, Co, and Fe) and La(7)Z(3) (Z = Pd, Rh, and Ru) superconductors are presented. The magnetic behaviour of the Th7X3 group has the characteristics of Pauli paramagnets. The La(7)Z(3) group also shows Pauli paramagnetism for Z = Pd and Ru, and signs of spin fluctuations for La7Rh3. Specific heat (C-p) measurements indicate a conventional BCS behaviour for La7Pd3 and La7Rh3, like that of the previously measured Th7X3 superconductors. in the case of La7Ru3, the reduced specific heat jump at the transition, the anomalous temperature dependence of C-p under magnetic field and a large upper critical field slope are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. |
| 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:000088047500002 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
78 |
| Permanent link to this record |
| |
|
| |
| Author |
Jaime, M.; Movshovich, R.; Stewart, G.R.; Beyermann, W.P.; Berisso, M.G.; Hundley, M.F.; Canfield, P.C.; Sarrao, J.L. |
| Title |
Closing the spin gap in the Kondo insulator Ce3Bi4Pt3 at high magnetic fields |
Type |
Journal Article |
| Year |
2000 |
Publication |
Nature |
Abbreviated Journal |
|
| Volume |
405 |
Issue |
6783 |
Pages |
160-163 |
| Keywords |
|
| Abstract |
Kondo insulator materials(1)-such as CeRhAs, CeRhSb, YbB12, Ce3Bi4Pt3 and SmB6-are 3d, 4f and 5f intermetallic compounds that have attracted considerable interest in recent years(2-5). At high temperatures, they behave like metals. But as temperature is reduced, an energy gap opens in the conduction band at the Fermi energy and the materials become insulating. This contrasts with other f-electron compounds, which are metallic at all temperatures. The formation of the gap in Kondo insulators has been proposed to be a consequence of hybridization between the conduction band and the f-electron levels(6,7), giving a 'spin' gap. If this is indeed the case, metallic behaviour should be recovered when the gap is closed by changing external parameters, such as magnetic field or pressure. Some experimental evidence suggests that the gap can be closed in SmB6 (refs 5, 8) and YbB12 (ref. 9). Here we present specific-heat measurements of Ce3Bi4Pt3 in d.c. and pulsed magnetic fields up to 60 tesla. Numerical results and the analysis of our data using the Coqblin-Schrieffer model demonstrate unambiguously a field-induced insulator-to-metal transition. |
| 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 |
0028-0836 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
ISI:000087080100043 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
300 |
| Permanent link to this record |
| |
|
| |
| Author |
Fainstein, A.; Maiorov, B.; Guimpel, J.; Nieva, G.; Osquiguil, E. |
| Title |
Annealing disorder and photoinduced order of oxygen chains in detwinned YBa2Cu3O6.65 single crystals probed by Raman scattering |
Type |
Journal Article |
| Year |
2000 |
Publication |
Physical Review B – Condensed Matter and Materials Physics |
Abbreviated Journal |
Phys. Rev. B Condens. Matter Mater. Phys. |
| Volume |
61 |
Issue |
6 |
Pages |
4298-4304 |
| Keywords |
|
| Abstract |
Raman scattering in detwinned YBa2Cu3O6.65 single crystals is studied as a function of photoexcitation and annealing. Copper-oxygen chain-related forbidden Raman bands that are known to strongly bleach with illumination at low temperatures, increase their intensity with chain fragmentation induced by annealing at high temperature. This contrasting behavior proves the conjunction of short Cu-O fragments into longer chains on photoexcitation. We interpret the Raman modes as due to vibrations at the end of CuO chain fragments and Cu-O-Cu monomers, and use their evolution with illumination and annealing as anisotropic sensitive markers of oxygen reordering processes. The identification of the “forbidden” Raman bands is discussed in the context of our results and recent literature in the subject. We also present absorption measurements performed on GdBa2Cu3Ox thin films with varying oxygen content. These experiments show that the 2.2-eV absorption and the chain-related Raman peaks have different dependencies with oxygen content and illumination, ruling out an explanation that suggests that the Raman intensity reduction of these modes is due to a photobleaching of intermediate defect states. These results highlight the potentialities of Raman scattering for oxygen dynamics studies and demonstrate the presence of photoinduced oxygen ordering in these high-Tc superconductor compounds. |
| Address |
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 |
01631829 (ISSN) |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
Cited By (since 1996): 18; Export Date: 17 April 2009; Source: Scopus; CODEN: PRBMD; Language of Original Document: English; Correspondence Address: Fainstein, A.; Centro At |
Approved |
no |
| Call Number |
BT @ osquigui @ |
Serial |
374 |
| Permanent link to this record |
| |
|
| |
| Author |
Herbsommer, J.A.; Nieva, G.; Luzuriaga, J. |
| Title |
Repetition of the disordered pattern in successive solidifications of vortex matter observed by Bitter decoration |
Type |
Journal Article |
| Year |
2000 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys. Rev. B |
| Volume |
62 |
Issue |
1 |
Pages |
678-681 |
| Keywords |
|
| Abstract |
Repeated images of the vortex structure in YBa2Cu3O7-delta Single crystals have been obtained, using the Bitter technique. By removing the iron dots between each decoration experiment, it is possible to image the vortices in different cooldown runs done under the same field and temperature conditions. The images show that these different realizations of a disordered vortex state found in twinned crystals are very similar at long range and differ only in small-scale detail. This is unusual behavior in glassy systems, where expectations are that successive configurations will differ over many scales. In contrast, ordered vortex crystals in clean samples can form with different orientations in different runs, therefore differing at long ranges. Double-sided decorations have been performed in twinned samples, and the correlation between images in both sides of the sample is similar in magnitude but slightly different qualitatively than that found in successive decorations. |
| 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:000088037000106 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
225 |
| Permanent link to this record |
| |
|
| |
| Author |
Pastoriza, H.; Candia, S.; Nieva, G. |
| Title |
Anisotropic vortex dynamics in twined YBaCuO single crystals |
Type |
Journal Article |
| Year |
2000 |
Publication |
Physica B |
Abbreviated Journal |
|
| Volume |
284-288 |
Issue |
2 |
Pages |
763-764 |
| Keywords |
|
| Abstract |
Rotating continuously the applied vortex force and measuring the vortex velocity vector, we were able to directly determine the role of twin boundaries in the vortex dynamics in YBa$2$Cu$3Ο_7$ single crystals with unidirectional twins. We show the different effect of these correlated pinning defects into the various vortex phases. In the entangled vortex liquid state, we observe a linear response but with an anisotropic viscosity. On the other hand, an anomalous guided motion by twin planes is found in the vortex solid. |
| 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 @ hernan @ pastoriza00 |
Serial |
39 |
| Permanent link to this record |
| |
|
| |
| Author |
Roa Rojas, J.; Jurelo, A.R.; Menegotto Costa, R.; Mendonca Ferreira, L.; Pureur, P.; Orlando, M.T.D.; Prieto, P.; Nieva, G. |
| Title |
Fluctuation conductivity and the dynamical universality class of the superconducting transition in the high-Tc cuprates |
Type |
Journal Article |
| Year |
2000 |
Publication |
Physica C: Superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
341-348 |
Issue |
3 |
Pages |
1911-1912 |
| Keywords |
|
| Abstract |
Systematic measurements of the fluctuation conductivity in several high-temperature superconducting cuprates show the occurrence of a genuine critical regime. The conductivity exponent is consistent with the predictions of the 3D-XY universality class and yields a dynamical critical exponent z = 1.5. |
| 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:000165855900185 |
Approved |
no |
| Call Number |
BT @ hernan @ |
Serial |
223 |
| Permanent link to this record |
