Joao Oliveira Ventura - Universidade do Porto
Joao Oliveira Ventura - Universidade do Porto
Joao Oliveira Ventura - Universidade do Porto
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<strong>Joao</strong> <strong>Oliveira</strong> <strong>Ventura</strong>PersonalDetailsGender: MaleDate of birth: 28th of January, 1977Place of birth: <strong>Porto</strong>, PortugalContactInformationResearchInterestsRua <strong>do</strong> Campo Alegre, 687 Voice (work): (351) 220402325Department of Physics Voice (mobile): (351) 966831320<strong>Porto</strong> University Fax: (351) 2204024064169-007 <strong>Porto</strong> E-mail: joventur@fc.up.ptPortugalWWW: http://www.fc.up.pt/pessoas/joventur/Nanotechnology, spintronics, nanostructures, magnetic nanostructures, nano-fabrication, lithography,e-beam lithography, ion beam deposition, sputtering deposition, magnetic arrays, <strong>do</strong>ts, anti<strong>do</strong>ts,magnetic tunnel junctions, MgO-based tunnel junctions, tunnel magnetoresistance, spin valves,specular spin valves, giant magnetoresistance, nano-oxide layers, nano-contacts, pinholes acrosstunnel barriers, electromigration, diffusion, ballistic transport, nanoporous alumina, self-organizedstructures, sensors, magnetoresistive sensors, memories, magnetic ran<strong>do</strong>m access memories, resistiveran<strong>do</strong>m access memories, exchange bias, training effect, nanostructure characterization, transportproperties, structural properties, computational simulation.Education Ph.D., Physics, Faculty of Sciences, <strong>Porto</strong> University, Portugal, May 2006.Dissertation Topic: Magnetic Nanostructures(http://www.fc.up.pt/pessoas/joventur/thesis.html)Advisor: Prof. J. B. Sousa.M.Sc., Computational Methods in Science and Engineering, Faculty of Engineering, <strong>Porto</strong> University,Portugal, 2001.Dissertation Topic: Simulation of X-ray diffraction spectra of nanostructured materialsAdvisor: Prof. J. Salgueiro da SilvaB.Sc., Physics, Faculty of Sciences, <strong>Porto</strong> University, Portugal, 1996–2000.Research ”Auxiliar” research scientist (at IFIMUP) May, 2008 - presentResearch scientist at IFIMUP on ”Micro- and Nano-Fabrication”, under Program Science 2007 fromFundacao para a Ciencia e Tecnologia.Post <strong>do</strong>c (at IFIMUP) June, 2006 - April, 2008Studies on the importance of metallic nanoconstrictions on the transport properties of AlO x magnetictunnel junctions (MTJs); evaluation of the existence of a ballistic component on the magnetoresistanceof AlO x -MTJs; magnetoresistance (MR) enhancement processes in MgO-tunnel junctions.Evidence of a large metallic contribution to the overall transport properties of thin, low resistanceMgO-MTJs (barrier thickness t = 6 Å, Resistance-Area product, R×A∼ 30 Ωµm 2 ), for whichMR∼60%.Fabrication of arrays of nano-elements (single thin films or exchange bias bilayers) by e-beam lithography,with different shapes, sizes and separations. Characterization by Scanning Electron Microscopy,Atomic and Magnetic Force Microscopies and Magneto-Optical Kerr Effect. Use of selforganizednanoporous alumina and ion beam deposition to fabricate arrays of magnetic anti<strong>do</strong>ts.
Magnetic and transport properties of two-dimensional nanogranular media and related sub-microndevices, POCTI/CTM/36489/00, team member.Nanostructured Magnetic Films with an Insulating Matrix, PRAXIS/P/CTM/11242/1998, grantresearcher.Thesis advisoryRefereeingOrganizingCommitteesPublications(Overall; 2002–)Jose Miguel Teixeira, Magnetic tunnel junctions, thin films and nanostructures, Ph.D. thesis underway(2006–).Physical Review B, Journal of Applied Physics, IEEE Transactions on Magnetism, Vacuum.Ninth International Workshop on Non-Crystalline Solids, Local Organizing Committee, <strong>Porto</strong>, Portugal,April 27–30, 2008.Publications in international scientific periodicals with referees: 30 (plus 9 accepted).Citations in international scientific periodicals with referees: 94 (source: ISI Web of Knowledge).h-index: 6 (m-index: 1; source: ISI Web of Knowledge).Publications Simulations of refrigeration on integrated circuits using micro-channels, A. M. Pereira, J. C. R. E.<strong>Oliveira</strong>, J. O. Costa, J. <strong>Ventura</strong>, J. B. Sousa, J. P. Araujo, accepted in J. Non-Cryst. Sol.Pinholes and the temperature dependent transport properties of MgO-based magnetic tunnel junctions,J. <strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo, J. B. Sousa, P. Wisniowski, P. P. Freitas, acceptedin Phys. Rev. B.Structural, magnetic and transport properties of ion beam deposited Co thin films, R. Fermento, D.Leito, J. M. Teixeira, A. M. Pereira, J.<strong>Ventura</strong>, J. P. Araujo, J. B. Sousa, accepted in J. Non-Cryst.Sol.Structural characterization of MnNi and MnPt antiferromagnetic materials for spintronic applications,J. <strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo, J. B. Sousa, V. Amaral, B. Negulescu, M. Rickartand P. P. Freitas, accepted in J. Non-Cryst. Sol.Characterization of electrodeposited Ni and Ni 80 Fe 20 nanowires, D. C. Leitao, C. T. Sousa, J. <strong>Ventura</strong>,J. S. Amaral, F. Carpinteiro, K. R. Pirota, M. Vazquez, J. B. Sousa, J. P. Araujo, accepted inJ. Non-Cryst. Sol.Anodization process of self-ordering nanoporous alumina membranes in phosphoric acid, M. Proenca,C. T. Sousa, D. C. Leitao, J. <strong>Ventura</strong>, J. B. Sousa, J. P. Araujo, accepted in J. Non-Cryst. Sol.Asymmetric electromigration-driven resistive switching in tunnel junctions, J. <strong>Ventura</strong>, J. P. Araujo,F. Carpinteiro, J. B. Sousa, Z. Zhang, Y. Liu and P. P. Freitas, accepted in J. Non-Cryst. Sol.Influence of surface pre-treatment on the pore growth of nanoporous alumina at room temperature,D. C. Leitao, C. Sousa, J. <strong>Ventura</strong>, J. P. Araujo, J. B. Sousa, accepted in Phys. Stat. Sol.Magnetic characterization of MnPt/CoFe bilayers using the MOKE technique, J. M. Teixeira, A. M.Pereira, J. <strong>Ventura</strong>, R. F. A. Silva, F. Carpinteiro, J. P. Araujo, J. B. Sousa, M. Rickart, S. Car<strong>do</strong>so,R. Ferreira and P. P. Freitas, accepted in Vacuum.
Training effect in specular spin valves, J. <strong>Ventura</strong>, J. P. Araujo, J. B. Sousa, A. Veloso and P. P.Freitas, Phys. Rev. B. 77, 184404 (2008).RKKY and Neel contributions to the interlayer coupling field of MnIr-based spin valves: Influenceof deposition rate, roughness and spacer thickness, J. M. Teixeira, J. <strong>Ventura</strong>, R. Fermento, J. P.Araujo, J. B. Sousa, S. Car<strong>do</strong>so and P. P. Freitas, J. Appl. Phys. 103, 07F319 (2008).Pinholes in thin low resistance MgO-based magnetic tunnel junctions probed by temperature dependenttransport measurements, J. <strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo, J. B. Sousa, P. Wisniowskiand P. P. Freitas, J. Appl. Phys. 103, 07A909 (2008).Three-state memory combining resistive and magnetic switching using tunnel junctions, J. <strong>Ventura</strong>,A. M. Pereira, J. P. Araujo, J. B. Sousa, Z. Zhang, Y. Liu and P. P. Freitas, J. Phys. D: Appl.Phys. 40, 5819 (2007).Distribution of blocking temperatures in nano oxide layers of specular spin valves, J. <strong>Ventura</strong>, J. P.Araujo, J. B. Sousa, A. Veloso and P. P. Freitas, J. Appl. Phys. 101, 113901 (2007).Interlayer coupling and magnetoresistance of MnIr-based spin valves: Dependencies on depositionrate, spacer thickness and temperature, J. M. Teixeira, J. <strong>Ventura</strong>, R. Fermento, J. P. Araujo, J. B.Sousa, S. Car<strong>do</strong>so and P. P. Freitas, IEEE Trans. Magn. 43, 3143 (2007).Temperature dependence of transport properties and exchange bias in MnNi based spin valves, J. M.Teixeira, J. <strong>Ventura</strong>, B. Negulescu, J. P. Araujo, R. Fermento, J. B. Sousa and P. P. Freitas, J.Magn. Magn. Mat. 316, e973 (2007).Spin dependent migration-conduction model for ultrathin magnetic tunnel junctions, Yu. G. Pogorelov,J. V. Lopes, J. <strong>Ventura</strong>, P. P. Freitas, R. Ferreira, J. P. Araujo and J. B. Sousa, J. Magn. Magn.Mat. 316, e957 (2007).Transport properties of low resistace underoxidized magnetic tunnel junctions, J. <strong>Ventura</strong>, R. Ferreira,J. M. Teixeira, J. P. Araujo, Y. Pogorelov, J. B. Sousa and P. P. Freitas, IEEE Trans. Magn. 43,2815 (2007).Influence of the <strong>do</strong>main structure of nano-oxide layers on the transport properties of specular spinvalves, J. <strong>Ventura</strong>, J. B. Sousa, A. Veloso and P. P. Freitas, J. Appl. Phys. 101, 09E502 (2007).Electrical current-driven pinhole formation and insulator-metal transition in tunnel junctions, J.<strong>Ventura</strong>, Z. Zhang, Y. Liu, J. B. Sousa and P. P. Freitas, J. Phys. Cond. Matt. 19, 176207 (2007).Competing spin-dependent conductance channels in under-oxidized tunnel junctions, J. <strong>Ventura</strong>, J.P. Araujo, J. B. Sousa, R. Ferreira and P. P. Freitas, Appl. Phys. Lett. 90, 032501 (2007).Dielectric break<strong>do</strong>wn in underoxidized magnetic tunnel junctions: Dependence on oxidation time andarea, J. <strong>Ventura</strong>, R. Ferreira, J. B. Sousa and P. P. Freitas, IEEE Trans. Magn. 42, 2658 (2006).Transport and magnetic properties of the Er 5 Si 4 compound, A. M. Pereira, J. P. Araujo, M. E.Braga, R. P. Pinto, J. <strong>Ventura</strong>, F. Correia, J. M. Teixeira, J. B. Sousa, C. Magen, P. A. Algarabel,L. Morellon and M. R. Ibarra, J. All. Comp. 423, 66 (2006).Electromigration-driven resistance switching in non-magnetic tunnel junctions, J. <strong>Ventura</strong>, A. Pereira,J. M. Teixeira, F. Carpinteiro, J. P. Araujo, J. B. Sousa, Y. Liu, Z. Zhang and P. P. Freitas, J. All.Comp. 423, 181 (2006).
Nanoscopic origin of Current Induced Switching in thin tunnel junctions, J. <strong>Ventura</strong>, J. P. Araujo,J. B. Sousa, Y. Liu, Z. Zhang and P. P. Freitas, IEEE Trans. Nanotechnol. 5, 142 (2006).Spin-dependent two-level resistance fluctuations in underoxidized tunnel junctions, J. <strong>Ventura</strong>, J. M.Teixeira, Yu. Pogorelov, J. B. Sousa, R. Ferreira and P. P. Freitas, J. Appl. Phys. 99, 08T301(2006).Short-range effects and magnetization reversal in Co 80 Fe 20 thin films: a MOKE magnetometry<strong>do</strong>mainimaging and AMR study, J. M. Teixeria, R. F. A. Silva, J. <strong>Ventura</strong>, A. Pereira, J. P. Araujo,M. Ama<strong>do</strong>, F. Carpinteiro, J. B. Sousa, S. Car<strong>do</strong>so, R. Ferreira and P. Freitas, Mat. Sci. Forum514-516, 1145 (2006).Heat generation in tunnel junctions for current-written pinned layer switching, J. <strong>Ventura</strong>, A.Pereira, J. M. Teixeira, J. P. Araujo, F. Carpinteiro, J. B. Sousa, Y. Liu, Z. Zhang and P. P.Freitas, Mat. Sci. Forum. 514-516, 323 (2006).Domain imaging, MOKE and AMR in CoFeB films for MRAM applications, J. M. Teixeria, R.Silva, J. <strong>Ventura</strong>, J. P. Araujo, J. B. Sousa, S. Car<strong>do</strong>so, R. Ferreira and P. P. Freitas, Mat. Sci.Eng. B 126, 180 (2006).Electromigration in thin tunnel junctions with ferromagnetic/nonmagnetic electrodes: Nanoconstrictions,heating, and direct and wind forces, J. <strong>Ventura</strong>, J. B. Sousa, Y. Liu, Z. Zhang and P. P. Freitas,Phys. Rev. B 72, 094432 (2005).Exchange coupling of bilayers and synthetic antiferromagnets pinned to MnPt, M. Rickart, A.Guedes, B. Negulesco, J. <strong>Ventura</strong>, J. B. Sousa, P. Diaz, M. MacKenzie, J. N. Chapman and P.P. Freitas, Eur. Phys. J. B, 45, 207 (2005).Blocking temperature in exchange coupled MnPt/CoFe bilayers and synthetic antiferromagnets, M.Rickart, A. Guedes, J. <strong>Ventura</strong>, J. B. Sousa and P. P. Freitas, J. Appl. Phys. 97, 10K110 (2005).Relaxation phenomena in current induced switching in thin magnetic tunnel junctions, J. <strong>Ventura</strong>,J. P. Araujo, F. Carpinteiro, J. B. Sousa, Y. Liu, Z. Zhang and P. P. Freitas, J. Magn. Magn. Mat.290-291, 1067 (2005).Peculiar magnetic and electrical properties near structural percolation in metal-insulator granularlayers, J. B. Sousa, J. A. M. Santos, R. F. A. Silva, J. M. Teixeira, J. <strong>Ventura</strong>, Yu. G. Pogorelov,G. N. Kakazei, S. Car<strong>do</strong>so, P. P. Freitas and E. Snoeck, J. Appl. Phys. 96, 3861 (2004).Exchange bias of MnPt/CoFe films prepared by ion beam deposition, M. Rickart, P. P. Freitas, I. G.Trindade, N. P. Barradas, E. Alves, M. Salgueiro, N. Muga, J. <strong>Ventura</strong>, J. B. Sousa, G. Proudfoot,D. Pearson and M. Davis, J. Appl. Phys. 95, 6317 (2004).Ferromagnetic coupling field reduction in CoFeB tunnel junctions deposited by Ion Beam, S. Car<strong>do</strong>so,R. Ferreira, P. P. Freitas, M. MacKenzie, J. Chapman, J. O. <strong>Ventura</strong>, J. B. Sousa and N. P. Barradas,IEEE Trans. Magn. 40, 2272 (2004).Impact of the magnetism of nano oxide layers on the GMR effect in specular spin valves, J. O.<strong>Ventura</strong>, J. B. Sousa, P. P. Freitas and A. Veloso, J. Magn. Magn. Mat. 272-276, 1892 (2004).Anomalous MR(H) behaviour of CoFe nano-oxide spin valves at low temperatures, J. O. <strong>Ventura</strong>, J.B. Sousa, M. A. Salgueiro da Silva, P. P. Freitas and A. Veloso, J. Appl. Phys. 93, 7690 (2003).Comparative study of magnetoresistance and magnetization in nano-oxide-specular and non-specular
MnIr/CoFe/Cu/CoFe spin-valves from 10 to 300 K, J. B. Sousa, J. O. <strong>Ventura</strong>, M. A. Salgueiro daSilva, P. P. Freitas and A. Veloso, J. Appl. Phys. 91, 5321 (2002). Selected for Journal of NanoscaleScience & Technology, April, 2002.Papers inpreparationInfluence of shape and magnetic material on the magneto-refrigeration process of integrated circuits,A. M. Pereira, J. C. Soares, J. <strong>Ventura</strong>, J. B. Sousa, J. P. Araujo and J. C. R. E. <strong>Oliveira</strong>, submitted.Influence of pinholes on MgO-tunnel junction barrier parameters obtained from current-voltage characteristics,J. <strong>Ventura</strong>, J. M. Teixeira, J. B. Sousa, R. Ferreira, P. P. Freitas, J. Langer, B. Ocker,W. Maass, submitted.Quantum effects in atomically perfect specular spin valve structures, J. M. Teixeira, J. <strong>Ventura</strong>, Y.Pogorelov, J. B. Sousa, submitted.ProceedingsDielectric break<strong>do</strong>wn in underoxidized magnetic tunnel junctions, J. <strong>Ventura</strong>, J. B. Sousa, R. Ferreiraand P. P. Freitas, Magnetic Nanostructures for Micro- Electromechanical Systems and SpintronicApplications, pg. 70 (2006), ISBN 88-8296-209-1.Electromigration in magnetic tunnel junctions, J. <strong>Ventura</strong>, J. P. Araujo, J. B. Sousa, Y. Liu, Z. Zhangand P. P. Freitas, Magnetic Nanostructures for Micro- Electromechanical Systems and SpintronicApplications, pg. 78 (2006), ISBN 88-8296-209-1.Presentations(Overall; 2002-)Invited oral presentations in international conferences: 2.Oral presentations in international conferences: 9.Poster presentations in international conferences: 32.Invited OralPresentationsTransport Mechanisms in Magnetic Tunnel Junctions, J. <strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo,J. B. Sousa, R. Ferreira, P. Wisniowski, Z. Zhang, Y. Liu and P. P. Freitas, Third InternationalSymposium on Medical, Bio- and Nano-Electronics, Sendai, Japan, 5-6 March, 2008.Current-Induced Switching in Magnetic Tunnel Junctions, P. P. Freitas, Z. Zhang, Y. Liu, J. Wang,J. <strong>Ventura</strong>, J. B. Sousa, A. Deac, O. Re<strong>do</strong>n and B. Dieny, 9th Joint MMM-Intermag Conference,Anaheim, USA, 5-9 January, 2004.OralPresentationsAsymmetry in resistive switching in magnetic tunnel junctions, J. <strong>Ventura</strong>, J. M. Teixeira, J. P.Arajo, J. B. Sousa, Z. Zhang, Y. Liu, P. P. Freitas, Ninth International Workshop on Non-CrystallineSolids, <strong>Porto</strong>, Portugal, 27 - 30 April, 2008.RKKY and Neel contributions to the interlayer coupling field of MnIr-based spin valves: influenceof deposition rate, roughness and spacer thickness, J. M. Teixeira, J. <strong>Ventura</strong>, R. Fermento, J. P.Araujo, J. B. Sousa, S. Car<strong>do</strong>so and P. P. Freitas, 52nd MMM Conference, Tampa, USA.Competing spin dependent transport mechanisms in low resistance underoxidized magnetic tunneljunctions, J. <strong>Ventura</strong>, R. Ferreira, J. M. Teixeira, J. P. Araujo, Y. Pogorelov, J. B. Sousa and P. P.Freitas, 10th Joint MMM/Intermag Conference, Baltimore, USA, 7 - 11 January, 2007.Magnetic properties of nano-oxide-layers in specular spin valves, J. <strong>Ventura</strong>, J. M. Teixeira, A. M.Pereira, J. B. Sousa, A. Veloso and P. P. Freitas, JEMS06 (III Joint European Magnetic Symposia),San Sebastian, Spain, 26-30 June, 2006.
Dielectric break<strong>do</strong>wn in underoxidized magnetic tunnel junctions, J. <strong>Ventura</strong>, R. Ferreira, J. B. Sousaand P. P. Freitas, Intermag 2006, San Diego, California, USA, May 8 - 12, 2006.Magnetic characterization of nanostructures for spintronics using the MOKE technique, J. M. Teixeira,R. F. A. Silva, J. <strong>Ventura</strong>, A. M. Pereira, J. P. Araujo, F. Carpinteiro, J. B. Sousa, S. Car<strong>do</strong>so,R. Ferreira, M. Rickart and P. P. Freitas, RIVA 5 - 5th Iberian Vacuum Meeting, Guimaraes, Portugal,18 - 21 September, 2005.Electromigration-driven resistance switching in magnetic and non-magnetic tunnel junctions, J. <strong>Ventura</strong>,J. M. Teixeira, J.P. Araujo, J. B. Sousa, Y. Liu, Z. Zhang and P. P. Freitas, European MaterialsResearch Society (EMRS) 2005 Fall Meeting, Warsaw, Poland, September 5-9, 2005.Specularity in high performance nano-oxide layer spin valves, J. M. Teixeira, J. <strong>Ventura</strong>, Yu. Pogorelov,J. B. Sousa, A. Veloso and P. P. Freitas, ICCE-12 - Twelfth Internationsl Conference on Composites/NanoEngineering, Tenerife, Spain, August 1-6, 2005.Magnetization reversal in CoFe thin films for spintronics: a MOKE magnetometry, <strong>do</strong>main imagingand AMR study, J. M. Teixeira, R. Silva, J. <strong>Ventura</strong>, J.P. Araujo, M. M. Ama<strong>do</strong>, F. Carpinteiro, J.B. Sousa, S. Car<strong>do</strong>so, R. Ferreira and P. P. Freitas, Materiais 2005, Aveiro, Portugal, March 20-23,2005.PosterPresentationsExchange bias relaxation in specular spin valves, J. <strong>Ventura</strong>, J. B. Sousa, A. Veloso and P. P. Freitas,JEMS08 (IV Joint European Magnetic Symposia), Dublin, Ireland, 14-19 September, 2008.Influence of shape and magnetic material on the refrigeration process for integrated circuits, A.M.Pereira, J. C. R. E. <strong>Oliveira</strong>, J.<strong>Ventura</strong>, J. P. Araujo, J. B. Sousa, 2nd International Conference onAdvanced Nano Materials, June 22nd -25th 2008, Aveiro, Portugal.Temperature dependent transport properties of electrodeposited Ni and Ni80Fe20 nanowires grownin alumina nanoporous templates, D. C. Leitao, C. T. Sousa, J. <strong>Ventura</strong>, J. Amaral, F. Carpinteiro,K. R. Pirota, M. Vazquez, J. B. Sousa and J.P. Araujo, 2nd International Conference on AdvancedNano Materials, June 22nd -25th 2008, Aveiro, Portugal.Structural, magnetic and transport properties of ion beam deposited Co thin films, J.<strong>Ventura</strong>, R.Fermento, D. Leito, J. M. Teixeira, A. M. Pereira, J. P. Araujo, J. B. Sousa, 2nd InternationalConference on Advanced Nano Materials, June 22nd -25th 2008, Aveiro, Portugal.Influence of pinholes on MgO-tunnel junction barrier parameters obtained from current-voltage characteristics,J.<strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo, J. B. Sousa, P. Wisniowski and P. P. Freitas, 2ndInternational Conference on Advanced Nano Materials, June 22nd -25th 2008, Aveiro, Portugal.Structural, magnetic and transport properties of ion beam deposited Co thin films, J.<strong>Ventura</strong>, R.Fermento, D. Leito, J. M. Teixeira, A. M. Pereira, J. P. Araujo, J. B. Sousa, 2nd InternationalConference on Advanced Nano Materials, June 22nd -25th 2008, Aveiro, Portugal.Anodization process of self-ordering nanoporous alumina membranes in phosphoric acid, M. P.Proenca, C. T. Sousa, D. C. Leitao, J. <strong>Ventura</strong>, F. Carpinteiro, J. B. Sousa, J. P. Araujo, NinthInternational Workshop on Non-Crystalline Solids, <strong>Porto</strong>, Portugal, 27 - 30 April, 2008.Characterization of electrodeposited Ni and Ni80Fe20 nanowires, D. C. Leitao, C. T. Sousa, J.<strong>Ventura</strong>, J. Amaral, F. Carpinteiro, K. R. Pirota, M. Vazquez, J. B. Sousa and J.P. Araujo, NinthInternational Workshop on Non-Crystalline Solids, <strong>Porto</strong>, Portugal, 27 - 30 April, 2008.Py anti<strong>do</strong>t thin films: a transport and magnetic characterization as a function of temperature, D. C.
Leitao, C. T. Sousa, J. <strong>Ventura</strong>, J. Amaral, F. Carpinteiro, K. R. Pirota, M. Vazquez, J. B. Sousaand J.P. Araujo, Ninth International Workshop on Non-Crystalline Solids, <strong>Porto</strong>, Portugal, 27 - 30April, 2008.Simulations on the refrigeration of integrated circuits using micro-channels, A. M. Pereira, J. C. R.E. <strong>Oliveira</strong>, J. C. Soares, J. <strong>Ventura</strong>, J.B. Sousa and J. P. Araujo, Ninth International Workshop onNon-Crystalline Solids, <strong>Porto</strong>, Portugal, 27 - 30 April, 2008.Structural properties of exchange biasing MnPt and MnNi antiferromagnetic materials for spintronic,J. <strong>Ventura</strong>, J.M. Teixeira, J.P. Arajo, J.B. Sousa, V. Amaral, B. Negulescu, M. Rickart, P.P. Freitas,Ninth International Workshop on Non-Crystalline Solids, <strong>Porto</strong>, Portugal, 27 - 30 April, 2008.Structural, magnetic and transport properties of ion beam deposited NiFe thin films, J.<strong>Ventura</strong>, R.Fermento, D. Leito, J. M. Teixeira, A. M. Pereira, J. P. Araujo, J. B. Sousa, Ninth InternationalWorkshop on Non-Crystalline Solids, <strong>Porto</strong>, Portugal, 27 - 30 April, 2008.Ordered Assembly of Oxide Nanotubes in a Porous Alumina Membrane, M. P. Proenca, C. T. Sousa,A. M. L. Lopes, D. C. Leitao, J. <strong>Ventura</strong>, J. B. Sousa, J. P. Araujo, NanoSpain 2008, Braga,Portugal, 14 - 18 April, 2008.Ordered Assembly of Oxide Nanotubes in a Porous Alumina Membrane, M. P. Proenca, C. T. Sousa,A. M. L. Lopes, D. C. Leitao, J. <strong>Ventura</strong>, J. B. Sousa, J. P. Araujo, ChemOnTubes 2008, Zaragoza,Spain, 6 - 9 April, 2008.Co anti<strong>do</strong>t thin films deposited on nanoporous alumina templates, C. Sousa, D. C. Leitao, J. <strong>Ventura</strong>,F. Carpinteiro, M. Ama<strong>do</strong>, J. P. Araujo and J. B. Sousa, MORIS 2007, Workshop on Thermal andOptical Magnetic Materials and Devices, Carnegie Mellon University, Pittsburgh, USA, 24 - 26September, 2007.Temperature dependent transport properties of thin low resistance MgO-based magnetic tunnel junctions,J. <strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo, J. B. Sousa, P. Wisniowski and P. P. Freitas, 52ndMMM Conference, Tampa, USA.Influence of surface pre-treatment on the pore growth of nanoporous alumina at room temperature,D. C. Leitao, C. Sousa, J. <strong>Ventura</strong>, J. P. Araujo, J. B. Sousa, European Materials Research Society(EMRS) 2007 Fall Meeting, Warsaw, Poland.Transport properties of low coupling field spin valves: dependencies on spacer thickness, depositionrate and temperature, J. M. Teixeira, J. <strong>Ventura</strong>, R. Fermento, J. P. Araujo, J. B. Sousa, S. Car<strong>do</strong>soand P. P. Freitas, 10th Joint MMM/Intermag Conference, Baltimore, USA, 7 - 11 January, 2007.Training effects in specular spin valves, J. <strong>Ventura</strong>, J. B. Sousa, A. Veloso and P. P. Freitas, 10thJoint MMM/Intermag Conference, Baltimore, USA, 7 - 11 January, 2007.Spin dependent migration-conduction model for ultrathin magnetic tunnel junctions, Yu. G. Pogorelov,J. V. Lopes, J. <strong>Ventura</strong>, P. P. Freitas and J. B. Sousa, JEMS06 (III Joint European Magnetic Symposia),San Sebastian, Spain, 26-30 June, 2006.Temperature dependence of transport properties and exchange bias in MnNi based spin valves, J. M.Teixeira, J. <strong>Ventura</strong>, A. M. Pereira, J. P. Araujo, R. Fermento, J. B. Sousa, B. Negulescu and P. P.Freitas, JEMS06 (III Joint European Magnetic Symposia), San Sebastian, Spain, 26-30 June, 2006.Electrical transport in low resistance underoxidized magnetic tunnel junctions, J. <strong>Ventura</strong>, J. M.Teixeira, Yu. G. Pogorelov, J. B. Sousa, R. Ferreira and P. P. Freitas, RIVA 5 - 5th Iberian Vacuum
Meeting, Guimaraes, Portugal, 18 - 21 September, 2005.Electromigration-driven resistance switching in tunnel junctions, J. <strong>Ventura</strong>, J. M. Teixeira, A.Pereira, J. P. Araujo, J. B. Sousa, Y. Liu, Z. Zhang and P. P. Freitas, 50th Conference on Magnetismand Magnetic Materials, San Jose, California, USA, October 30 - November 3, 2005.Spin-dependent two-level resistance jumps in underoxidized magnetic tunnel junctions, J. <strong>Ventura</strong>, J.M. Teixeira, Yu. Pogorelov, J. B. Sousa, R. Ferreira and P. P. Freitas, 50th Conference on Magnetismand Magnetic Materials, San Jose, California, USA, October 30 - November 3, 2005.Thermopower in advanced specular spin valves, A. Pereira, J. <strong>Ventura</strong>, J. M. Teixeira, M. E. Braga,R. Pinto, J. B. Sousa, A. Veloso and P. P. Freitas, European Materials Research Society (EMRS)2005 Fall Meeting, Warsaw, Poland, September 5-9, 2005.Domain imaging, MOKE and AMR in CoFeB films for MRAM applications, J. M. Teixeira, R. Silva,J. <strong>Ventura</strong>, J.P. Araujo, J. B. Sousa, S. Car<strong>do</strong>so, R. Ferreira and P. P. Freitas, European MaterialsResearch Society (EMRS) 2005 Spring Meeting, Strasbourg, France, May 31-June 3, 2005.Current-induced electromigration in metal-insulator interfaces: potential applications for multi-statemagnetic tunnel junctions, J. <strong>Ventura</strong>, J. M. Teixeira, J.P. Araujo, F. Carpinteiro, J. B. Sousa, Y.Liu, Z. Zhang and P. P. Freitas, Materiais 2005, Aveiro, Portugal, March 20-23, 2005.Exchange bias and blocking temperature in MnPt/CoFe bilayers and synthetic antiferromagnets,M. Rickart, A. Guedes, B. Negulesen, P. P. Freitas, J. <strong>Ventura</strong>, J. B. Sousa, M. Mackenzie andJ. Chapman, 49th Conference on Magnetism and Magnetic Materials, Jacksonville, Florida, USA,November 7-11, 2004.Temperature dependence of Current Induced Switching in thin magnetic tunnel junctions, J. <strong>Ventura</strong>,J. P. Araujo, F. Carpinteiro, J. B. Sousa, Y. Liu, Z. Zhang and P. P. Freitas, 49th Conference onMagnetism and Magnetic Materials, Jacksonville, Florida, USA, November 7-11, 2004.Relaxation phenomena in Current Induced Switching in thin magnetic tunnel junctions, J. <strong>Ventura</strong>,J. P. Araujo, F. Carpinteiro, J. B. Sousa, Y. Liu, Z. Zhang, P. P. Freitas, Joint European MagneticSymposia (JEMS), Dresden, Germany, September 05-10, 2004.Ferromagnetic coupling field reduction in CoFeB tunnel junctions deposited by Ion Beam, S. Car<strong>do</strong>so,R. Ferreira P. P. Freitas, M. MacKenzie, J. Chapman, J. O. <strong>Ventura</strong>, J. B. Sousa and N.P.Barradas,9th Joint MMM-Intermag Conference, Anaheim, USA, January 5-9, 2004.Impact of the magnetism of nano oxide layers on the GMR effect in specular spin valves, J. O.<strong>Ventura</strong>, J. B. Sousa, P. P. Freitas and A. Veloso, International Conference on Magnetism, Rome,Italy, July 27 - August 1, 2003.Anomalous MR(H) behaviour of CoFe nano-oxide spin valves at low temperatures, J. O. <strong>Ventura</strong>,J. B. Sousa, M. A. Salgueiro da Silva, P. P. Freitas and A. Veloso, 47th Annual Conference onMagnetism and Magnetic Materials, Tampa, Florida, USA, November 2002.OralPresentations inWorkshopsTransport Mechanisms in Magnetic Tunnel Junctions, J. <strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo, J. B.Sousa, P. Wisniowski, Z. Zhang, Y. Liu and P. P. Freitas, Fourth IFIMUP open day, <strong>Porto</strong>, Portugal,18 June, 2008.Resistive switching in magnetic tunnel junctions, J. <strong>Ventura</strong>, J. M. Teixeira, J. P. Araujo, J. B.Sousa, Y. Liu, Z. Zhang and P. P. Freitas, 14th Workshop on Magnetism and Intermetallics, Coimbra,Portugal, February 14-15 2008.
Magnetic properties of nano-oxide layers in specular spin valves, J. <strong>Ventura</strong>, J. B. Sousa, A. Velosoand P. P. Freitas, 13th Workshop on Magnetism and Intermetallics, <strong>Porto</strong>, Portugal, February 8-92007.Electrical transport in low resistance underoxidized magnetic tunnel junctions, J. <strong>Ventura</strong>, J. B.Sousa, R. Ferreira and P. P. Freitas, 12th Workshop on Magnetism and Intermetallics, Sacavem,Portugal, February 9-10 2006.Schools2nd Workshop on Low-Dimensional Structures: Properties and Applications, Aveiro, Portugal, January31 - February 1, 2008.European School On Nanosciences and Nanotechnologies, Grenoble, France, August 26 – September15, 2007.International School on Structural Characterization of Nanostructures, Aveiro, Portugal, January24-27, 2007.Magnetic Nanostructures for Micro-Electromechanical Systems and Spintronic Applications, NATO-ASI School, Reggio Calabria, Italy, July 2-15, 2006.Nanomagnetism and Spintronics, Spring School, Cargese, France, May 24 – June 3, 2005.
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