A5079891666- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Magneto-Optical Properties and Applications
- Magnetic Properties and Applications
- Surface and Thin Film Phenomena
- Theoretical and Computational Physics
- Characterization and Applications of Magnetic Nanoparticles
- ZnO doping and properties
- Photonic Crystals and Applications
- 2D Materials and Applications
- Copper Interconnects and Reliability
- Graphene research and applications
- Semiconductor materials and interfaces
- Metal and Thin Film Mechanics
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Fluid Dynamics and Turbulent Flows
- Gender Diversity and Inequality
- Heusler alloys: electronic and magnetic properties
- Magnetic Field Sensors Techniques
- Multiferroics and related materials
- Force Microscopy Techniques and Applications
- MXene and MAX Phase Materials
- Electron and X-Ray Spectroscopy Techniques
- Advanced Materials Characterization Techniques
Instituto de Tecnologías Físicas y de la Información “Leonardo Torres Quevedo”
2020-2024
Instituto de Información Científica y Tecnológica
2023-2024
Consejo Superior de Investigaciones Científicas
2001-2023
Universidad Politécnica de Madrid
2012-2023
Institute of Micro and Nanotechnology
2018-2020
Universidad Centroccidental Lisandro Alvarado
2020
Juan Agustín Maza University
2018
Centro Nacional de Microelectrónica
2012-2017
McGill University
2010-2011
Instituto de Física Fundamental
2009-2011
We present magnetoresistance experiments in magnetic Ni nanocontacts the ballistic transport regime at room temperature. It is shown that for a few-atom contact reaches values of $280%$ temperature and applied fields 100 Oe. Results are presented over 50 samples showing trend smaller larger response. This indicates effect arises just nanocontact.
Abstract In recent years, spin–orbit effects have been widely used to produce and detect spin currents in spintronic devices. The peculiar symmetry of the Hall effect allows creation a accumulation at interface between metal with strong interaction magnetic insulator, which can lead net pure current flowing from into insulator. This applies torque on magnetization, eventually be driven steady motion. Tailoring this experiment extended films has proven elusive, probably due mode competition....
We present theory and experiments in good agreement for ballistic magnetoresistance nanoscopic-size contacts 3 $d$ metals (Ni Co). It is found that values of the magnetoconductance $\ensuremath{\sim}300%$ at room temperature can be explained by scattering domain wall which trapped constriction region. These are obtained very small they decrease fast as contact size increases. The also explains this behavior.
It is demonstrated that the threshold current for damping compensation can be reached in a 5 μm diameter YIG(20 nm)|Pt(7 nm) disk. The demonstration rests upon measurement of ferromagnetic resonance linewidth as function I(dc) using magnetic force microscope (MRFM). shown losses spin-wave modes existing insulator reduced or enhanced by at least factor depending on polarity and intensity an in-plane dc flowing through adjacent normal metal with strong spin-orbit interaction. Complete...
Abstract The exfoliation of two naturally occurring van der Waals minerals, graphite and molybdenite, arouse an unprecedented level interest by the scientific community shaped a whole new field research: 2D materials research. Several years later, family that can be exfoliated to isolate keeps growing, but most them are synthetic. Interestingly, in nature, plenty minerals found with wide range chemical compositions crystal structures whose properties mostly unexplored so far. This...
Abstract Due to their nonlinear properties, spin transfer nano-oscillators can easily adapt frequency external stimuli. This makes them interesting model systems study the effects of synchronization and brings some opportunities improve microwave characteristics in view applications information communication technologies and/or design innovative computing architectures. So far, mutual through propagating spinwaves exchange coupling a common magnetic layer has been demonstrated. Here we show...
We study experimentally with submicrometer spatial resolution the propagation of spin waves in microscopic waveguides based on nanometer-thick yttrium iron garnet and Pt layers. demonstrate that by using spin-orbit torque, length such systems can be increased nearly a factor 10, which corresponds to increase spin-wave intensity at output 10 μm long transmission line three orders magnitude. also show that, regime, where magnetic damping is completely compensated amplification suppressed...
We have fabricated nanometer-sized magnetic tunnel junctions using a conductive tip nanoindentation technique in order to study the transport properties of single metallic nanoparticle. Coulomb blockade effects show clear evidence for single-electron tunneling through 2.5nm Au cluster. The observed magnetoresistance is signature spin conservation during process nonmagnetic
P-n junctions based on vertically stacked single or few layer transition metal dichalcogenides (TMDCs) have attracted substantial scientific interest. Due to the propensity of TMDCs show exclusively one type conductivity, n- p-type, heterojunctions different materials are typically fabricated produce diode-like current rectification and photovoltaic response. Recently, artificial, stable substitutional doping MoS2 into p-type has been demonstrated. is an interesting material use for...
We present experimental results of unprecedented large magnetoresistance obtained in stable electrodeposited Ni–Ni nanocontacts 10–30 nm diameter. The contacts exhibit up to 700% at room temperature and low applied fields and, therefore, act as very effective spin filters. These values the are attributed ballistic transport through a magnetic “dead layer” contact width about 1 or smaller. Nanometer sized, high sensitive magnetoresistive sensors could become key elements for storage...
We present measurements of the electric potential fluctuations on surface highly oriented pyrolytic graphite using electrostatic force and atomic microscopy. Micrometric domainlike distributions are observed even when sample is grounded. Such unexpected given good metallic conductivity because should be an equipotential. Our results indicate coexistence regions with "metalliclike" "insulatinglike" behaviors showing large order 0.25 V. In lower quality graphite, this effect not observed....
We report on an experimental study the spin-waves relaxation rate in two series of nanodisks diameter ϕ=300, 500, and 700 nm, patterned out systems: a 20 nm thick yttrium iron garnet (YIG) film grown by pulsed laser deposition either bare or covered 13 Pt. Using magnetic resonance force microscope, we measure precisely ferromagnetic linewidth each individual YIG YIG|Pt nanodisks. find that nanostructure is sensibly smaller than one measured extended film. Analysis frequency dependence...
This study explores experimentally the stochastic nature of domain wall depinning in permalloy nanowires using notches various shapes and depths. The presence notch is detected through its anisotropic magnetoresistance (AMR), which measured with high precision order to detect even small changes profile. These measurements showed that variations field are related changes, sometimes very small, AMR profile, indicates pinned profile can affect largely process. As these many times unpredictable...
Nanofabrication has allowed the development of new concepts such as magnetic logic and race-track memory, both which are based on displacement domain walls nanostripes. One issues that to be solved before devices can meet market demands is stochastic behaviour wall movement in Here we show nature motion permalloy nanostripes suppressed at very low fields (0.6-2.7 Oe). We also find different field regimes for this match well with propagation modes. The highest pinning probability found around...
Abstract Excitation of magnetization dynamics by pure spin currents has been recently recognized as an enabling mechanism for spintronics and magnonics, which allows implementation spin-torque devices based on low-damping insulating magnetic materials. Here we report the first spatially-resolved study dynamic modes excited current in nanometer-thick microscopic Yttrium Iron Garnet disks. We show that these exhibit nonlinear self-broadening preventing formation self-localized bullet, plays a...
Magnonics rely on the wave nature of magnetic excitations to process information, an approach that is common many fields such as photonics, phononics, and plasmonics. Nevertheless, magnons, quanta spin-wave excitations, have unique advantage be at frequencies are lying between a few GHz tens GHz, is, in technologically relevant radio-frequency bands for 4G 5G telecommunications. Furthermore, their typical wavelengths compatible with on-chip integration. Here, we demonstrate signal filtering...
We show that ballistic magnetoresistance exhibits universal scaling in atomic or nanometer scale contacts. Plotting the data as conductance, we find that, if maximum magnetoconductance is normalized to unity and conductance scaled with conductivity of bulk material, fall a narrow region, independent nanocontact materials, for our four sets from literature. The results agree theory takes into account spin-scattering within magnetic-domain wall.
Conduction electrons in graphite are expected to have micrometer large de Broglie wavelength as well mean free path. A direct influence of these lengths the electric transport properties finite-size samples was neglected past. We provide a evidence this effect through size dependence magnetoresistance, which decreases with sample even for hundreds micrometers large. Our findings may explain absence magnetoresistance small few graphene layers and ask general revision experimental theoretical...
This letter shows that the ballistic magnetoresistance of Fe at room temperature and low magnetic fields is ten times smaller than for Ni Co. The results are well explained by theory provides a global understanding 3d transition metals because, Fe, ratio majority to minority spins Fermi level much data indicate conduction carried out d electrons in case contrast what happens
The authors present results on current induced domain wall motion in Co∕Cu∕CoFeB trilayered stripes. threshold densities are around 106A∕cm2 at zero field, i.e., about two orders of magnitude smaller than single NiFe is assisted when the field torque acts same direction as spin torque. When opposed to transfer one and above a observe reversible displacement (peak dV∕dI measurements). This can be ascribed onset fluctuations, which confirmed by micromagnetic simulations.
The temperature in a ferromagnetic nanostripe with notch subject to Joule heating has been studied detail. We first performed an experimental real-time calibration of the versus time as 100 ns current pulse was injected into Permalloy nanostripe. This repeated for different amplitudes and stripe dimensions set curves were fitted computer simulation using Fourier thermal conduction equation. best fit these obtained by including temperature-dependent behavior electrical resistivity...
Strongly out-of-equilibrium regimes in magnetic nanostructures exhibit novel properties, linked to the nonlinear nature of magnetization dynamics, which are great fundamental and practical interest. Here, we demonstrate that ferromagnetic resonance driven by microwave fields can occur with substantial spatial coherency at an unprecedented large angle precessions, is normally prevented onset spin-wave instabilities turbulent dynamics. Our results show this limitation be overcome nanomagnets,...
Noncontact ultrasonic spectroscopy (NCUS) is used to excite and sense thickness resonances in films of polypropylene ferroelectrets. From the comparison these measurements with theoretical calculations it possible extract some material properties: film density, velocity, attenuation ultrasounds variation two magnitudes frequency. Hence elastic compliance acoustic impedance are worked out. Observed frequency exhibits classical viscoelastic behavior which can be investigate underlaying...
We present the parametric excitation of spin-wave modes in YIG micro-disks via parallel pumping. Their spectroscopy is performed using magnetic resonance force microscopy (MRFM), while their spatial profiles are determined by micro-focus Brillouin light scattering (BLS). observe that almost all fundamental eigenmodes an in-plane magnetized micro-disk, calculated a micromagnetic eigenmode solver, can be excited pumping scheme, as opposed to transverse one. The comparison between MRFM and BLS...