ULTIMATE-I

ULTIMATE-I researchers from Argentina, Luis Avilés and Julián Milano from CNEA / @Resonanlab / Instituto Balseiro, Bariloche win Argentinian national PICT projects in #spintronics and magnetic materials.

Two projects are funded by the Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación.

The topics of the projects are Spin Dynamics in Micro- and Nanostructures (Luis Avilé) and Control of acoustic and spin wave propagation through ferromagnetic thin films with periodic domain patterns (Julian Milano).

The goal of the projects is to investigate the spin transport phenomena in magnetic micro- and nanostructures for the generation, detection and control of spin currents!

Looking forward to the results of these projects!

Manipulating the magnetization of materials on extremely short time scales, in the picosecond range, is a highly coveted grail for information technologies. The complex magneto-optical techniques currently used are difficult to integrate spintronics into devices. To overcome these constraints, Juan Carlos Rojas-Sánchez of the Institut Jean Lamour (CNRS/Université de Lorraine) and one of the PIs of the ULTIMATE-I project has received an ERC Consolidator grant for his Magnetallien project.

In spintronics, components are controlled by a quantum parameter of electrons: the spin. This approach promises much more powerful and energy-efficient integrated circuits and components but faces many technical challenges.

“To achieve this goal, I am interested in materials where there is a strong coupling between spin and orbit,” explains Juan Carlos Rojas-Sánchez, a CNRS researcher at the Institut Jean Lamour (CNRS/Université de Lorraine). For example, when an electric current is passed through a platinum nanowire, it scatters the electrons in opposite directions according to their spin orientation, creating a spin current that can be injected into an adjacent magnetic layer. This phenomenon has applications such as memories, sensors or the realization of logic circuits.

Different approaches are envisaged to study and control this key ingredient: the spin-orbit coupling. For example, by generating a spin current in a thin layer of magnetic material and injecting it into a neighbouring layer. Understanding and exploiting this phenomenon on the picosecond time scale remains a challenge. It is currently only possible to obtain a signal of up to a hundred gigahertz using lasers and particularly “heavy” optical means,” notes Juan Carlos Rojas-Sanchez. I want to reduce the cost and size of the devices by exploiting new physical systems that use spin-orbit interaction.

To this end, he has set up the MAGNETALLIEN project, for which he has just been awarded this ERC Consolidator grant.

Original in French: https://factuel.univ-lorraine.fr/node/22436

Friday, December 16, at 11 a.m. Buenos Aires Time, Prof. Dr José Santiso gave a seminar entitled “Strain effects in vanadium dioxide films with the metal-insulator electronic transition” at “Laboratorio de Física de Superficies e Interfaces”, Instituto de Física del Litoral (IFIS-Litoral, CONICET-UNL).

José Santiso is a researcher at the Catalan Institute of Nanoscience and Nanotechnology (ICN2) in Barcelona, Spain. Dr Santiso, invited by Dr Mario C. G. Passeggih is part of the ULTIMATE-I (Ultra Thin Magneto Thermal Sensoring) project supported by the European Union.

The following is a brief summary.

Vanadium dioxide (VO₂)is an archetypical material showing a metal-insulator (M-I) Mott transition at about T=68C with several orders of magnitude change in the resistivity between the semiconducting low-T M1 phase and the high-T metallic rutile R phase. It has been proposed as a good candidate directly for Resistive-Random Access Memory (RRAM) devices or as complementary selector in combination of a bipolar RRAM device because of its high on/off ratio, fast switching speed and high current density. Although in bulk form the transition is above room temperature either chemical doping or mechanical strain have been demonstrated to bring the transition closer or even below room temperature making it very attractive in different devices. This work studies the structure features across transition of high quality strained epitaxial VO₂ films deposited on isostructural rutile TiO₂ (001) single crystals. Since M-I transition in VO₂ is accompanied by a structural change between monoclinic M1 phase and tetragonal R phase, with substantial variation in cell parameters, the nucleation of the high-T R phase embedded in the low-T M1 phase during transition, is expected to generate local interfacial regions with a large strain. The characterization of the structural features of the films by means of synchrotron X-ray Diffraction upon thermal cycles revealed the formation of local strain effects during the phase transition in competition with the epitaxial strain induced by the growth on the mismatched TiO₂ substrates. Such interphase regions between M1 and R crystal domains are submitted to a uniaxial strain (overlapped to the biaxial in-plane epitaxial strain) that stabilizes other polytypic VO₂ insulating phases (monoclinic M2, and triclinic transitional M3 or T phase) beyond their expected stability regions.[1] Concomitant to the subtle structural distortions a slight rotation of the monoclinic crystal domains occurs to accommodate the elastic energy constraints. The persistence of the coexistence of those polytypic phases even at room temperature turns VO₂ into a complex heterogeneous material. Nonetheless, at conditions where XRD of the films seems to indicate a pure rutile R phase, HRTEM analysis revealed a certain degree of heterogeneity at the nanoscale forming an intricate tweed pattern of other polytypes with different arrangements of V-V dimers along the c-axis direction [2], still displaying a metallic character. Altogether these observations evidence that VO₂ micro and nanostructure, and therefore its electrical response, depends on a subtle balance of unconventional strain relaxation mechanisms.

[1] L. Rodríguez, F. Sandiumenge, C. Frontera, J.M. Caicedo, J. Padilla, G. Catalán, J. Santiso, Strong strain gradients and phase coexistence at the metal-insulator transition in VO₂ epitaxial films, Acta Mater. 220 (2021) 117336.

[2] F. Sandiumenge, L. Rodríguez, M. Pruneda, C. Magén, J. Santiso, G. Catalan, Metallic Diluted Dimerization in VO₂ Tweeds, Adv. Mater. 33 (2021) 2004374.

ULTIMATE-I members from Chile, Serbia, and Spain participated and presented their new results on magnetism and spintronics during the annual conference of the Chilean Physical Society held at Universidad Técnica Federico Santa María (USM), Valparaíso, Chile.

Paolo Vavassori from nanoGune in Spain gave a talk on Ultrafast control of magnetization by light.

Mario Mery, Claudio Gonzalez, J. E. Valdés, Vanina Franco, Myriam H. Aguirre, and Carlos Garcia presented a poster on the Ferromagnetic response of NiO irradiated with H2 and He+ ion beams. Their work included research performed by three project partner organizations (CONICET from Argentina, UNIZAR from Spain, and USM from Chile).

ULTIMATE-I secondment to Centro Atómico Bariloche’s Magnetic Resonance Laboratory: Héloïse Damas, Juan-Carlos Rojas-Sánchez (both IJL/UL/CNRS – France), Igor Stanković (IPB/SenzorInfiz – Serbia), and Paolo Vavassori (CIC nanoGUNE – Spain).

A high level of interaction during the secondment provides us with a productive period regarding knowledge transfer, scientific idea exchange and discussion.

We finished another successful LATAM SPINTRONICS #spinargentina2022.

Thanks to all attendees for developing a respectful, friendly environment, especially Alejandro Butera, Luis Avilés Félix & Resonance Lab. for their excellent job.

Stay tuned for the next LATAM SPIN in 2024.

ULTIMATE-I participation in SPIN Argentina 2022 – Workshop on Spintronics
6 – 11 November 2022, San Carlos de Bariloche, Argentina

Invited talks:

L. B. Steren, INN-Conicet, Argentina, Control of magnetism by electric fields and strains in oxide-based multiferroics.
J. Curiale, Instituto de Nanociencia y Nanotecnología, CNEA– CONICET, Río Negro, Argentina, Universal critical exponents of the magnetic domain wall depinning transition.
Andrew D. Kent, Center for Quantum Phenomena, Dept. of Physics, New York University, USA, Spin-orbit Torques in Antiferromagnet Insulator/Heavy Metal Heterostructures.
P. Vavassori, CIC nanoGUNE BRTA, Spain, Plasmon-assisted nanomagnetic logics.

Contributed talks:

J. E. Gómez, Centro Atómico Bariloche, CNEA, INN, CONICET, Argentine, Tungsten crystal structure: Its role on the spin transport parameters.
H. Damas, Université de Lorraine, CNRS, France, Currentinduced Self-Torque in GdFeCo ferrimagnet.
I. Stanković, Scientific Computing Laboratory, University of Belgrade, Serbia, Tubular structures of magnetic particles – an accessible platform for curvilinear nanomagnetism.
M.A. Laguna–Marco. Instituto de Nanociencia y Materiales de Aragón, Zaragoza, Spain, Optimizating the performance of IrO₂ by doping: Ir_1–xM_xO₂ thin films (M = Sn, Cr, Co).

and 22 posters, among them:

Lara Solís (CNEA): ”FMR and thermal spin pumping enhanced by perpendicular anisotropy in YIG/Pt bilayers”; authors: Lara M. Solís, Santiago Carreira, Javier Gómez, Javier Briático, Abdelmadjid Anane, Alejandro Butera, Laura Steren, Myriam H. Aguirre

Sindy Rodríguez (CONICET): “Recognition of switching events in molecular nanoprobe experiment: an application to study spin transport”; authors: S.J. Rodríguez, A. Moya , M.H. Aguirre, M.C.G. Passeggi, R. Ibarra, D. Serrate

Sindy Rodríguez (CONICET); poster presentation: “Planar surfaces of point dipoles as a platform for 2d magnetic structure research”; authors: I. Stankovic, M. Passeggi, M. Aguirre, C. García

J. Martín Núñez (CONICET): “Synthesis and magneto-transport properties of FeO@Fe3O4@MgO@Fe3O4 onion-like magnetic nanoparticles”; authors: Jorge M. Núñez , Víctor Leborán , Francisco Rivadulla, Gerardo. F. Goya, Roberto D. Zysler , Myriam H. Aguirre, Elin L. Winkler

International Workshop on Spintronics – Spin Argentina 2022 started today.

Between November 7 and 11, around 125 participants from different parts of the world will enjoy in 36 invited talks, 24 contributed, 56 posters, and between presenters four 2022 IEEE Magnetic Society Distinguished Lecturers.

The participants will exchange their latest results and ideas about  #magnetism, #magnetic materials and their applications! In these 4 weeks of classes and experiments, they will explore different aspects of magnetism and spintronics.

The Workshop includes two networking activities: Meet the experts on Monday at 8:30 pm at a location to be defined, and Women in Magnetism on Tuesday at 8 pm at the same hotel as the conference.

Meet the experts provides PhD students and PostDocs with an opportunity to participate in a small-group discussion and get advice on career planning, technical paper writing, publication, job searches, research opportunities, or societal involvement. NETWORKING ACTIVITIES sponsored by the IEEE Magnetics Society Initiative to “Promote Magnetism in LATAM”.

Women in Magnetism event will propose a discussion about motivation programs for girls/young students in different countries The discussed topics will be: (1) the motivation of young female students for STEM careers (from primary school to university), and (2) Gender equality and science: from laws to social and work visibility.

Please also check the website, https://fisica.cab.cnea.gov.ar/spin2022/, for complete information.

This Spin Argentina event is possible thanks to the « historical » support of Gen Tatara, which has been joined this year by IEEE Magnetic Society and IOP Publishing Latinoamerica, CONICET, INN, CNEA, Fundación Balsiero, Instituto Balseiro, and MINCYT. The school is actively supported by the Ultra-Thin Magneto Thermal-SensorIng (ULTIMATE-I) project of the European Commission and in particular its participating organizations French Centre National de la Recherche Scientifique (CNRS), and the University of Zaragoza (UNIZAR), coordinator.

SPIN Argentina Workshop follows the School of Magnetism and Magnetic Materials, also supported by ULTIMATE-I, and many teachers and students will join the conference creating synergies.

International Workshop on Spintronics – Spin Argentina 2022 is two weeks away. We will be around 125 participants from different parts of the world!!

We will have the four 2022 IEEE Magnetic Society Distinguished Lecturers, 36 invited speakers, 24 oral contributions, 56 posters, and about 10 more attendees so far.

Please also check the website, https://fisica.cab.cnea.gov.ar/spin2022/, for updates.

This Spin Argentina event is possible thanks to the “historical” support of Gen Tatara, which has been joined this year by our project Ultimate-I (Ultra Thin Magneto Thermal Sensoring supported by the European Union), and the IEEE Magnetic Society, as well as IOP Publishing Latinoamerica, CONICET, INN, CNEA, Fundación Balsiero, Instituto Balseiro, and MINCYT.

This has allowed us to keep costs to a minimum and to be able to give about 30 waivers to students and young post-docs from different parts of the world. More recently, thanks to the IEEE initiative to Promote Magnetism in LATAM, we can support partially covering travel and accommodation expenses for LATAM students. And to organize networking activities.

We have two networking activities: Meet the experts on Monday at 8:30 pm at a location to be defined, and Women in Magnetism on Tuesday at 8 pm at the same hotel as the conference. Everyone is invited to participate. More details of these events will be shared later and will also be posted on the website.