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Author Haberkorn, N.; Suárez, S.; Pérez, P.D.; Troiani, H.; Granell, P.; Golmar, F.; Lee, J.-H.; Moon, S.H.
Title (up) 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 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
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Author Navarro, H.; Sirena, M.; González Sutter, J.; Troiani, H.E.; del Corro, P.G.; Granell, P.; Golmar, F.; Haberkorn, N.
Title (up) 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 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).
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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
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Author Sutter, J.G.; Sarmiento Chavez, A.; Soria,; Granada, M.; Neñer, L.; Bengió, S.; Granel, P.; Golmar, F.; Haberkorn, H.; Leyva, G.; Sirena, M.
Title (up) Stress and disorder effect in the physical properties of artificially engineered multiferroic superlattices Type Journal Article
Year 2021 Publication Materials Chemistry and Physics Abbreviated Journal Materials Chemistry and Physics
Volume 271 Issue Pages 124910
Keywords
Abstract La0·8Ba0·2MnO3, Ba0·25Sr0·75TiO3 and BaTiO3 superlattices were grown to study the influence of structural disorder on the physical properties of multiferroic multilayers. Controlling the lattice mismatch of the superlattices allowed growing structures with different growth mechanisms. The manganite layers in the samples were used as “sensor layers”, that respond to the structural changes in the superlattices, induced by changing the thickness and nature of the ferroelectric layers. Stress has a weak influence on the magnetic properties of these systems. Transport properties are characterized by a high temperature thermally activated regime and a low temperature variable hopping one. The strain and structural disorder in the samples increases the localization energy of the current carriers for both regimes. Important interface effects can be achieved controlling the strain and disorder in the interfaces, allowing tuning the metal-insulator transition temperature. These results help to further understand the role of interface effects in the development of manganite based ferromagnetic/ferroelectric multilayered systems.
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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 0254-0584 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 875
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Author Haberkorn, N.; Guimpel, J.; Suárez, S.; Troiani, H.E.; Granell, P.; Golmar, F.; Lee, J.-H.; Moon, S.H.; Lee, H.
Title (up) 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 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.
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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
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Author Haberkorn, N.; Bengio, S.; Troiani, H.; Suárez, S.; Pérez, P.D.; Granell, P.; Golmar, F.; Sirena, M.; Guimpel, J.
Title (up) 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 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
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Author Sutter, J.G.; Chávez, A.S.; Soria, S.; Granada, M.; Neñer, L.; Bengió, S.; Granell, P.; Golmar, F.; Haberkorn, N.; Leyva, A.G.; Sirena, M.
Title (up) Tuning the magneto-electrical properties of multiferroic multilayers through interface strain and disorder Type Journal Article
Year 2020 Publication Journal of Alloys and Compounds Abbreviated Journal J. Alloys Compd.
Volume Issue Pages 157820
Keywords multiferroic; superlattices; manganites; magnetism; disorder
Abstract Artificially engineered superlattices were designed and fabricated to induce different growth mechanisms and structural characteristics. DC sputtering was used to grow ferromagnetic (La0.8Ba0.2MnO3)/ferroelectric (Ba0.25Sr0.75TiO3 or BaTiO3) superlattices. We systematically modified the thickness of the ferromagnetic layer to analyze dimensional and structural disorder effects on the superlattices with different structural characteristics. The crystalline structure was characterized by X-ray diffraction and transmission electron microscopy. The magnetic and electronic properties were investigated by SQUID magnetometry and resistance measurements. The results show that both strain and structural disorder can significantly affect the physical properties of the systems. Ba0.25Sr0.75TiO3 based superlattices with a low thickness of the ferromagnetic layers (4 nm.) present compressive strain that decreases the ferromagnetic transition temperature from 250 K corresponding to the unstressed samples to 230 K. In these samples, the localization energy of the charge carrier through the electron-phonon interaction decreases at low temperatures (∼100 meV). Ba0.25Sr0.75TiO3 based superlattices with thicknesses of the ferromagnetic layers higher than 12 nm present tensile strain that reduces the charge carrier localization energy at low temperatures (∼1 meV), increasing the ferromagnetic transition temperature (Tc∼265K). Structural defects in BaTiO3 based superlattices have a stronger influence on the magnetic properties than on the transport properties. Nevertheless, disorder blocks the ferromagnetic transition for highly disordered samples (thickness of the ferromagnetic layer < 3 nm). These results help to further understand the role of strain and interface effects in the magnetic and transport properties of manganite based multiferroic systems.
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 0925-8388 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 861
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Author Sutter, J.G.; Sarmiento Chávez, A.; Soria, S.; Granada, M.; Neñer, L.; Bengió, S.; Granell, P.; Golmar, F.; Haberkorn, N.; Leyva, A.G.; Sirena, M.
Title (up) Tuning the magneto-electrical properties of multiferroic multilayers through interface strain and disorder Type Journal Article
Year 2021 Publication Journal of Alloys and Compounds Abbreviated Journal J. Alloys Compd.
Volume 859 Issue Pages 157820
Keywords
Abstract Artificially engineered superlattices were designed and fabricated to induce different growth mechanisms and structural characteristics. DC sputtering was used to grow ferromagnetic (La0.8Ba0.2MnO3)/ferroelectric (Ba0.25Sr0.75TiO3 or BaTiO3) superlattices. We systematically modified the thickness of the ferromagnetic layer to analyze dimensional and structural disorder effects on the superlattices with different structural characteristics. The crystalline structure was characterized by X-ray diffraction and transmission electron microscopy. The magnetic and electronic properties were investigated by SQUID magnetometry and resistance measurements. The results show that both strain and structural disorder can significantly affect the physical properties of the systems. Ba0.25Sr0.75TiO3 based superlattices with a low thickness of the ferromagnetic layers (4 nm) present compressive strain that decreases the ferromagnetic transition temperature from 250 K corresponding to the unstressed samples to 230 K. In these samples, the localization energy of the charge carrier through the electron-phonon interaction decreases at low temperatures (∼100 meV). Ba0.25Sr0.75TiO3 based superlattices with thicknesses of the ferromagnetic layers higher than 12 nm present tensile strain that reduces the charge carrier localization energy at low temperatures (∼1 meV), increasing the ferromagnetic transition temperature (Tc∼265 K). Structural defects in BaTiO3 based superlattices have a stronger influence on the magnetic properties than on the transport properties. Nevertheless, disorder blocks the ferromagnetic transition for highly disordered samples (thickness of the ferromagnetic layer < 3 nm). These results help to further understand the role of strain and interface effects in the magnetic and transport properties of manganite based multiferroic systems.
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 0925-8388 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 874
Permanent link to this record
 

 
Author Haberkorn, N.; Coulter, Y.; Condó, A.M.; Granell, P.; Golmar, F.; Ha, H.S.; Moon, S.H.
Title (up) Vortex creep and critical current densities Jc in a 2μm thick SmBa2Cu3O7−d coated conductor with mixed pinning centers grown by co-evaporation Type Journal Article
Year 2016 Publication Superconductor Science and Technology Abbreviated Journal
Volume 29 Issue Pages 075011
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 748
Permanent link to this record