|   | 
Details
   web
Records
Author Haberkorn, N.; Suárez, S.; Pérez, P.D.; Troiani, H.; Granell, P.; Golmar, F.; Lee, J.-H.; Moon, S.H.
Title Effect of mixed pinning landscapes produced by 6 MeV oxygen irradiation on the resulting critical current densities Jc in 1.3 µm thick GdBa2Cu3O7-d coated conductors grown by co-evaporation Type Journal Article
Year 2017 Publication Physica C: Superconductivity and its Applications Abbreviated Journal Physica C
Volume (down) 542 Issue Pages 6-11
Keywords Coated conductors; Vortex dynamics; Glassy exponents; Irradiation
Abstract We report the influence of crystalline defects introduced by 6 MeV 16O3+ irradiation on the critical current densities Jc and flux creep rates in 1.3 µm thick GdBa2Cu3O7-δ coated conductor produced by co-evaporation. Pristine films with pinning produced mainly by random nanoparticles with diameter close to 50 nm were irradiated with doses between 2 × 1013 cm−2 and 4 × 1014 cm−2. The irradiations were performed with the ion beam perpendicular to the surface of the samples. The Jc and the flux creep rates were analyzed for two magnetic field configurations: magnetic field applied parallel (H║c) and at 45° (H║45°) to the c-axis. The results show that at temperatures below 40 K the in-field Jc dependences can be significantly improved by irradiation. For doses of 1 × 1014 cm−2 the Jc values at μ0H = 5 T are doubled without affecting significantly the Jc at small fields. Analyzing the flux creep rates as function of the temperature in both magnetic field configurations, it can be observed that the irradiation suppresses the peak associated with double-kink relaxation and increases the flux creep rates at intermediate and high temperatures. Under 0.5 T, the flux relaxation for H‖c and H||45° in pristine films presents characteristic glassy exponents μ = 1.63 and μ = 1.45, respectively. For samples irradiated with 1 × 1014 cm−2, these values drop to μ = 1.45 and μ = 1.24, respectively
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 Approved no
Call Number BT @ pedrazp @ Serial 771
Permanent link to this record
 

 
Author Curiale, J.; Sánchez, R.D.; Troiani, H.E.; Pastoriza, H.; Levy, P.; Leyva, A.G.
Title Morphological and magnetic characterization of manganites oxide based nanowires and nanotubes Type Journal Article
Year 2004 Publication Physica B Abbreviated Journal
Volume (down) 354 Issue 1-4 Pages 98-103
Keywords
Abstract A morphological and magnetic study of sub-micrometric nanostructures of a manganese oxide-based compound La0.325Pr0.300Ca0.375MnO3 is presented. Nanowires of 50 and 100 nm and tubes with external diameters of 200 and 800 nm were synthesized. Scanning electron microscopy with EDS microanalysis (SEM) and transmission electron microscopy (TEM) allowed to characterize the morphology and microstructure of these nanostructures. The walls of the nanotubes are composed of on average 40 nm grain size particles, while in nanowires the grains are much smaller, in the range between 4 and 20 nm. In both situations, the small grains present a random crystalline orientation, as it is confirmed by TEM diffraction experiments. Magnetization measurements and hysteresis loops are presented and discussed based on magnetic interaction between the grains, anisotropy considerations and reversal magnetization mechanisms.
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 @ curiale04 Serial 10
Permanent link to this record
 

 
Author Haberkorn, N.; Troiani, H.; Condó, A.M.; Wang, H.; Mao, Q.; Fang, M.
Title Vortex dynamics in phase separated Tl0.58Rb0.42Fe1.72Se2 crystals Type Journal Article
Year 2016 Publication Solid State Communications Abbreviated Journal
Volume (down) 247 Issue Pages 88
Keywords
Abstract
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 751
Permanent link to this record
 

 
Author Haberkorn, N.; Bengio, S.; Troiani, H.; Suárez, S.; Pérez, P.D.; Granell, P.; Golmar, F.; Sirena, M.; Guimpel, J.
Title Thickness dependence of the superconducting properties of γ- Mo<inf>2</inf>N thin films on Si (001) grown by DC sputtering at room temperature Type Journal Article
Year 2018 Publication Materials Chemistry and Physics Abbreviated Journal Mater. Chem. Phys
Volume (down) 204 Issue Pages 48-57
Keywords
Abstract
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 Cited By :1; Export Date: 14 March 2018 Approved no
Call Number BT @ jguimpel @ Serial 785
Permanent link to this record
 

 
Author Curiale, J.; Sánchez, R.D.; Troiani, H.E.; Ramos, C.A.; Pastoriza, H.; Leyva, A.G.; Levy, P.
Title Magnetism of manganite nanotubes constituted by assembled nanoparticles Type Journal Article
Year 2007 Publication Phys. Rev. B Abbreviated Journal
Volume (down) 75 Issue Pages 224410
Keywords
Abstract We present the study of the magnetic properties of manganite nanotubes with 800 nm of external diameter and 3-5 μm length. The study includes two ferromagnetic compounds, La0.67Ca0.33MnO3 and La0.67Sr0.33MnO3, and one with ferromagnetic and charge ordered phase coexistence, La0.325Pr0.300Ca0.375MnO3. In this case, the walls are formed by grains and have approximately thickness of 150 nm and the most probable grain size is 70 nm. For the ferromagnetic nanotubes smaller values are observed, between 45 and 60 nm for the thickness and 25 nm for the grain size, respectively. In La0.325Pr0.300Ca0.375MnO3 we observe distinctive features comparing with the ferromagnetic nanotubes. After cooling below T$_C$ the samples at $H=0$, the first magnetization curve shows a gradual growth of the magnetization until reach a maximum value, which depends of H. After this, the material presents expected ferromagnetic hysteresis loops. Also, significant differences between the cooling and warming magnetization processes and large linewidth in the ferromagnetic resonances are observed. These experimental facts are explained in terms of the competition between the charge ordered and the ferromagnetic phases, including strong interaction among these last regions. Observations of dipolar interactions between the magnetic grains are evidenced by isothermal remanent magnetization and direct current demagnetization experiments.
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 @ curiale07 Serial 11
Permanent link to this record
 

 
Author Haberkorn, N.; Guimpel, J.; Suárez, S.; Troiani, H.E.; Granell, P.; Golmar, F.; Lee, J.-H.; Moon, S.H.; Lee, H.
Title Strong influence of the oxygen stoichiometry on the vortex bundle size and critical current densities J c of GdBa 2 Cu 3 O x -coated conductors grown by co-evaporation Type Journal Article
Year 2017 Publication Superconductor Science and Technology Abbreviated Journal Supercond. Sci. Technol.
Volume (down) 30 Issue 9 Pages 095009
Keywords
Abstract We report on the influence of oxygen stoichiometry on the vortex creep mechanism of GdBa 2 Cu 3 O x -coated conductors produced by co-evaporation. The oxygen stoichiometry of the films, x , was modified in a controlled way between 6.85 and 7, which resulted in systematic and reversible control of the superconducting critical temperature between about 78 and 93 K. The change in the oxygen stoichiometry produces a strong reduction in the self-field critical current densities J c without significantly modifying the power-law dependence at intermediate magnetic fields, which indicates a negligible contribution of oxygen vacancies to the pinning. In addition, the characteristic glassy exponent μ shows a systematic diminution from about 1.63 at x = 7 to about 1.12 at x = 6.85. The results are compared with those obtained for proton- and oxygen-irradiated films, in which the vortex dynamics is determined by a balance between the improved pinning, originating from nanocluster inclusion, and the suppressed superconducting properties due to disorder in the nanoscale.
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 0953-2048 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 775
Permanent link to this record
 

 
Author Navarro, H.; Sirena, M.; González Sutter, J.; Troiani, H.E.; del Corro, P.G.; Granell, P.; Golmar, F.; Haberkorn, N.
Title Electrical transport across nanometric SrTiO3 and BaTiO3 barriers in conducting/insulator/conducting junctions Type Journal Article
Year 2018 Publication Materials Research Express Abbreviated Journal
Volume (down) 5 Issue 1 Pages 016408
Keywords
Abstract We report the electrical transport properties of conducting/insulator/conducting heterostructures by studying current–voltage IV curves at room temperature. The measurements were obtained on tunnel junctions with different areas (900, 400 and 100 μ m 2 ) using a conducting atomic force microscope. Trilayers with GdBa 2 Cu 3 O 7 (GBCO) as the bottom electrode, SrTiO 3 or BaTiO 3 (thicknesses between 1.6 and 4 nm) as the insulator barrier, and GBCO or Nb as the top electrode were grown by DC sputtering on (100) SrTiO 3 substrates For SrTiO 3 and BaTiO 3 barriers, asymmetric IV curves at positive and negative polarization can be obtained using electrodes with different work function. In addition, hysteretic IV curves are obtained for BaTiO 3 barriers, which can be ascribed to a combined effect of the FE reversal switching polarization and an oxygen vacancy migration. For GBCO/BaTiO 3 /GBCO heterostructures, the IV curves correspond to that expected for asymmetric interfaces, which indicates that the disorder affects differently the properties at the bottom and top interfaces. Our results show the role of the interface disorder on the electrical transport of conducting/insulator/conduction heterostructures, which is relevant for different applications, going from resistive switching memories (at room temperature) to Josephson junctions (at low temperatures).
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 2053-1591 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 772
Permanent link to this record