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Author Haberkorn, N.; Guimpel, J.; Sirena, M.; Steren, L.B.; Campillo, G.; Saldarriaga, W.; Gomez, M.E.
Title Interface disorder and transport properties in HTC/CMR superlattices Type Journal Article
Year (up) 2004 Publication PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS Abbreviated Journal
Volume 408 Issue Pages 896-897
Keywords
Abstract The physical properties of superlattices are affected by interface disorder, like roughness and interdiffusion. X-ray diffraction allows its measurement through modeling and structure refinement. The high-T-c RBa2Cu3O7 (RBCO) and colossal magneto resistance La(x)A(1-x)MnO(3) (LAMO) perovskites are interesting superlattice partners given their similar lattice parameters and because the combination of magnetic and superconducting properties is interesting for both basic and applied research. We have investigated the structural and transport properties of YBCO/La2/3Ca1/3MnO3 and GdBCO/La0.6Sr0.04MnO3 superlattices grown by sputtering on (100)MgO. We find a roughness of 1 RBCO unit cell and a 30% interdiffusion in the same length from the interfaces for all samples. The superconducting behavior is found strongly dependent on the LAMO layer thickness. (C) 2004 Elsevier B.V. All rights reserved.
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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 0921-4534 ISBN Medium
Area Expedition Conference
Notes ISI:000224051700375 Approved no
Call Number BT @ hernan @ Serial 160
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Author Sirena, M.; Haberkorn, N.; Granada, M.; Steren, L.B.; Guimpel, J.
Title Oxygen and disorder effect in the magnetic properties of manganite films Type Journal Article
Year (up) 2004 Publication JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 272 Issue Pages 1171-1173
Keywords
Abstract We have made a systematic study of the magnetic properties of low doped manganite films submitted to different oxygenation treatments. We have found that oxygenation dynamics depends critically of the strain field in the sample. The T-C and the Mr increase as the oxygen content is increased. A decrease of the coercive field of the LSMO-STO films was observed, indicating that annealing treatments increase the oxygen content reducing oxygen vacancies. (C) 2004 Elsevier B.V. All rights reserved.
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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 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:000222236700179 Approved no
Call Number BT @ hernan @ Serial 162
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Author Haberkorn, N.; Sirena, M.; Guimpel, J.; Steren, L.B.
Title Disorder influence on the magnetic properties of La0.55Sr0.45MnO3/SrTiO3 superlattices Type Journal Article
Year (up) 2004 Publication JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 272 Issue Pages 1244-1246
Keywords
Abstract The structural and physical properties of La0.55Sr0.45MnO3/SrTiO3 superlattices grown by magnetron sputtering are studied. Two deposition temperatures and different mismatched substrates and buffer layers were used. The structure was determined by refinement through X-ray diffraction pattern fitting. The results indicate 1 unit cell (u.c.) interdiffusion at the interfaces and a 1 u.c. layer thickness fluctuation, i.e. roughness. In-plane hysteresis loops show the expected ferromagnetic behavior, while the perpendicular-to-plane hysteresis loops show anomalies which could evidence magnetic domain size inhomogeneities and stress. (C) 2004 Elsevier B.V. All rights reserved.
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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 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:000222236700212 Approved no
Call Number BT @ hernan @ Serial 163
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Author Granada, M.; Maiorov, B.; Sirena, M.; Steren, L.B.; Guimpel, J.
Title Hall effect in La0.6Sr0.4MnO3 thin films Type Journal Article
Year (up) 2004 Publication JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Abbreviated Journal
Volume 272 Issue Pages 1836-1838
Keywords
Abstract We studied the temperature and thickness dependence of the transport properties of La0.6Sr0.4MnO3 films. Hall voltage and magnetoresistance measurements on 10 and 150 nm thick films were performed with this porpose. From the ordinary Hall component, we calculated the density of carriers, which has hole-character and is systematically lower than that expected from the chemical composition of the manganite in both samples. Localization effects observed at low temperature in the resistivity of the thinner film, associated with the substrate-induced disorder, are correlated with a decrease of the density of carriers. (C) 2003 Elsevier B.V. All rights reserved.
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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 0304-8853 ISBN Medium
Area Expedition Conference
Notes ISI:000222236800084 Approved no
Call Number BT @ hernan @ Serial 164
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Author Haberkorn, N.; Guimpel, J.; Sirena, M.; Steren, L.B.; Saldarriaga, W.; Baca, E.; Gomez, M.E.
Title Antiferromagnetism at the YBa2Cu3O7/La2/3Ca1/3MnO3 interface Type Journal Article
Year (up) 2004 Publication Applied Physics Letters Abbreviated Journal Appl. Phys. Lett.
Volume 84 Issue 19 Pages 3927-3929
Keywords
Abstract The magnetic properties of a series of YBa2Cu3O7-x/La2/3Ca1/3MnO3 (YBCO/LC1/3MO) superlattices grown by dc sputtering at high oxygen pressures (3.5 mbar) show the expected ferromagnetic behavior. However, field-cooled hysteresis loops at a low temperatures show the unexpected existence of exchange bias effect associated with the existence of ferromagnetic/antiferromagnetic (AF) interfaces. The blocking temperature (T-B) is found to be thickness dependent and the exchange bias field (H-EB) is found to be inversely proportional to the ferromagnetic layer thickness, as expected. The presence of an AF material is probably associated with interface disorder and Mn valence shift toward Mn4+. (C) 2004 American Institute of Physics.
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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 0003-6951 ISBN Medium
Area Expedition Conference
Notes ISI:000221210100069 Approved no
Call Number BT @ hernan @ Serial 165
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Author Guimpel, J.; Haberkorn, N.; Sirena, M.; Steren, L.B.; Saldarriaga, W.; Baca, E.; Gomez, M.E.
Title Interface effects in perovskite superlattices Type Journal Article
Year (up) 2004 Publication JOURNAL OF LOW TEMPERATURE PHYSICS Abbreviated Journal
Volume 135 Issue 1-2 Pages 115-118
Keywords
Abstract The effect of interface disorder in perovskite superlattices, either with the substrate or between layers dominates the physics of the material, even when the lattice parameter of the component materials differs in less than 1%. Unexpected behavior emerges, like exchange bias in a system where no antiferromagnetic material has been included in the superlattice design.
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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 0022-2291 ISBN Medium
Area Expedition Conference
Notes ISI:000189139000012 Approved no
Call Number BT @ hernan @ Serial 166
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Author Sirena, M.; Haberkorn, N.; Granada, M.; Steren, L.B.; Guimpel, J.
Title Oxygen and disorder effect in the magnetic properties of manganite films Type Journal Article
Year (up) 2004 Publication Journal of Magnetism and Magnetic Materials Abbreviated Journal Proceedings of the International Conference on Magnetism (ICM 2003)
Volume 272-276, Part 2 Issue Pages 1171-1173
Keywords Manganite fims; Oxigenation; Magnetic properties
Abstract We have made a systematic study of the magnetic properties of low doped manganite films submitted to different oxygenation treatments. We have found that oxygenation dynamics depends critically of the strain field in the sample. The TC and the Mr increase as the oxygen content is increased. A decrease of the coercive field of the LSMO-STO films was observed, indicating that annealing treatments increase the oxygen content reducing oxygen vacancies.
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 0304-8853 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ jguimpel @ Serial 622
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Author Sirena, M.; Haberkorn, N.; Granada, M.; Steren, L.B.; Guimpel, J.
Title Metal-insulator transition induced by postdeposition annealing in low doped manganite films Type Journal Article
Year (up) 2009 Publication JOURNAL OF APPLIED PHYSICS Abbreviated Journal
Volume 105 Issue 3 Pages
Keywords
Abstract We studied the transport and magnetic properties of low-doped manganite films after different oxygenation processes. The oxygen content was adjusted by postdeposition annealing at different oxygen pressures and annealing times. For all the samples we observed an increase in the Curie temperature and the remnant magnetization with the oxygen content. In general, for decreasing number of oxygen vacancies, samples under expansive strain become more homogeneous and their electrical resistivity decreases. A metal-insulator transition is induced in highly oxygenated films grown on SrTiO3, probably related to a shift of the mobility edge crossing below the Fermi energy. We found that the oxygenation dynamics depend critically on the strain field induced by the substrates and also on the Sr doping concentration.
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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 0021-8979 ISBN Medium
Area Expedition Conference
Notes ISI:000263409700057 Approved no
Call Number BT @ hernan @ Serial 143
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Author Sirena, M.; Zimmers, A; Haberkorn, N.; Kaul, E.E.; Steren, L.B.; Lesueur, J.; Wolf, T.; Le Gall, Y.; Grob, J.-J.; Faini, G.
Title Direct observation of electronic inhomogeneities induced by point defect disorder in manganite films Type Journal Article
Year (up) 2010 Publication Journal of Applied Physics Abbreviated Journal JAP
Volume 107 Issue Pages 113903
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 @ ekaul @ Serial 633
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Author Sirena, M.; Kaul, E.; Pedreros, M.B.; Rodriguez, C.A.; Guimpel, J.; Steren, L.B.
Title Structural, magnetic and electrical properties of ferromagnetic/ferroelectric multilayers Type Journal Article
Year (up) 2011 Publication Journal of Applied Physics Abbreviated Journal J. Appl. Phys.
Volume 109 Issue 12 Pages 123920
Keywords atomic force microscopy; barium compounds; electrical conductivity; ferroelectric materials; ferromagnetic materials; lanthanum compounds; magnetic multilayers; magnetisation; multiferroics; sputter deposition; strontium compounds; superlattices; texture; tunnelling; X-ray diffraction
Abstract The La0.75Sr0.25MnO3 (LSMO)/Ba0.7Sr0.3TiO3 (BSTO) superlattices and bilayers, where LSMO is ferromagnetic and BSTO is ferroelectric, were grown by dc sputtering. X-ray diffraction indicates that the samples present a textured growth with the c axis perpendicular to the substrate. Magnetization measurements show a decrease of the sample’s magnetization for decreasing ferromagnetic thickness. This effect could be related to the presence of biaxial strain and a magnetic dead layer in the samples. Conductive atomic force microscopy indicates that the samples present a total covering of the ferromagnetic layer for a ferroelectric thickness higher than four unit cells. Transport tunneling of the carriers seems to be the preferred conduction mechanism through the ferroelectric layer. These are promising results for the development of multiferroic tunnel junctions.
Address
Corporate Author Thesis
Publisher Aip 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 @ jguimpel @ Serial 606
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