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Author (up) Niebieskikwiat, D.; Civale, L.; Balseiro, C.A.; Nieva, G.
Title Nonglassy relaxation by double kinks in YBa2Cu3O7-delta with columnar defects Type Journal Article
Year 2000 Publication PHYSICAL REVIEW B Abbreviated Journal
Volume 61 Issue 10 Pages 7135-7141
Keywords
Abstract We present long-term relaxation measurements of the irreversible magnetization in YBa2Cu3O7-delta Single crystals with columnar defects. Within the single vortex pinning regime we find a nonglassy response at intermediate currents, in between the half loops and superkinks glassy regimes. We demonstrate that such behavior is due to double kink excitations whose critical nucleus has a size independent of current, and occur even in the presence of pinning energy dispersion.
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:000085985800092 Approved no
Call Number BT @ hernan @ Serial 229
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Author (up) Osquiguil, E.; Kaul, E.E.; Tosi, L.; Balseiro, C.A.
Title Effects of spin density wave quantization on the electrical transport in epitaxial Cr thin films Type Journal Article
Year 2012 Publication Physical Review B Abbreviated Journal Phys. Rev. B
Volume 85 Issue Pages 104410
Keywords
Abstract We present measurements of the electrical resistivity ρ in epitaxial Cr films of different thicknesses grown on MgO (100) substrates, as a function of temperature T. The ρ(T) curves display hysteretic behavior in a certain temperature range, which is film thickness dependent. The hysteresis are related to the confinement of quantized incommensurate spin density waves (ISDW) in the film thickness. Our important finding is to experimentally show that the temperature Tmid where the ISDW changes from N to N+1 nodes decreases as the film thickness increases. Identifying Tmid with a first-order transition between ISDW states with N and N+1 nodes, and using a Landau approach to the free energy of the ISDW together with Monte Carlo simulations, we show that the system at high temperatures explores all available modes for the ISDW, freezing out in one particular mode at a transition temperature that indeed decreases with film thickness L. The detailed dependence of Tmid(L) seems to depend rather strongly on the boundary conditions at the Cr film interfaces.
Address Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica, 8400 Bariloche, Argentina
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 Approved no
Call Number BT @ pedrazp @ Serial 640
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Author (up) Osquiguil, E.; Tosi, L.; Kaul, E.E.; Balseiro, C.A.
Title On the origin of the low temperatures resistivity minimum in Cr thin films Type Journal Article
Year 2013 Publication Journal Of Applied Physics Abbreviated Journal J. Appl. Phys.
Volume 114 Issue 24 Pages 7 pp
Keywords
Abstract We present measurements of the electrical resistivity and Hall coefficient, p and R-H, in Cr films of different thicknesses grown on MgO (100) substrates, as a function of temperature T and applied magnetic field H. The results show a low temperature minimum in rho(T), which is thickness dependent. From 40K to 2K, the Hall coefficient is a monotonous increasing function as T is reduced with no particular signature at the temperature T-min, where the minimum develops. We explain the resistivity minimum assuming an imperfect nesting of the Fermi surface leading to small electron and hole pockets. We introduce a phenomenological model which supports this simple physical picture. (C) 2013 AI Publishing LLC.
Address [Osquiguil, E.] Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina
Corporate Author Thesis
Publisher Amer Inst Physics Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979 ISBN Medium
Area Expedition Conference
Notes WOS:000329173200042 Approved no
Call Number BT @ hernan @ Serial 682
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Author (up) Tosi, L.; Osquiguil, E.; Kaul, E.E.; Balseiro, C.A.
Title Barkhausen-type noise in the resistance of antiferromagnetic Cr thin films Type Journal Article
Year 2012 Publication Europhysics Letters Abbreviated Journal Europhys. Lett.
Volume 100 Issue Pages 67005
Keywords
Abstract We present an experimental study of the changes generated on the electrical resistance R(T ) of epitaxial Cr thin films by the transformation of quantized spin density wave domains as the temperature is changed. A characteristic resistance noise appears only within the same temperature region where a cooling-warming cycle in R(T ) displays hysteretic behavior. We propose an analysis based on an analogy with the Barkhausen noise seen in ferromagnets. There fluctuations in the magnetization M (H) occur when the magnetic field H is swept. By mapping

M → Ψ0 and H → T , where Ψ0 corresponds to the order parameter of the spin density wave, we generalize the Preisach model in terms of a random distribution of resistive hysterons to explain our results. These hysterons are related to distributions of quantized spin density wave domains with different sizes, local energies and number of nodes.
Address Centro Atómico Bariloche, Comisión Nacional de Energía Atómica – 8400 Bariloche, Argentina
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 650
Permanent link to this record