A5078712653- Magnetic properties of thin films
- Magnetic Properties and Applications
- Physics of Superconductivity and Magnetism
- Magnetic Field Sensors Techniques
- Magnetic and transport properties of perovskites and related materials
- Magneto-Optical Properties and Applications
- Theoretical and Computational Physics
- Characterization and Applications of Magnetic Nanoparticles
- Metallic Glasses and Amorphous Alloys
- Multiferroics and related materials
- Non-Destructive Testing Techniques
- ZnO doping and properties
- Magnetic Properties of Alloys
- Anodic Oxide Films and Nanostructures
- Sensor Technology and Measurement Systems
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Superconducting Materials and Applications
- Ferroelectric and Piezoelectric Materials
- Electric Motor Design and Analysis
- Law, logistics, and international trade
- Copper Interconnects and Reliability
- International Maritime Law Issues
- Maritime Security and History
- Smart Materials for Construction
Universidad Politécnica de Madrid
2014-2024
Institute of Micro and Nanotechnology
2016-2021
University of Cambridge
2001-2010
Centro Nacional de Microelectrónica
2007
University of Central Missouri
1998
Universidad Complutense de Madrid
1996
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....
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...
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 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...
The precise control and stabilization of magnetic domain walls is key for the development next generation nano-devices. Among multitude configurations a wall, topologically protected states are particular interest due to their intrinsic stability. In this work, using XMCD-PEEM, we have observed wall in ferromagnetic cylindrical nanowire. Its structure stabilized by periodic sharp alterations chemical composition large stability contrasts with mobility other non-protected non-chiral also...
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 describe experimental difficulties, and associated artefacts, that arose during the study of thin epitaxial films proposed multiferroic materials BiFeO3 BiMnO3. The problems experienced include large leakage currents charge injection from Nb-doped SrTiO3 substrates used as bottom electrodes. Charge prevents ferroelectric hysteresis loop closure contributes to apparent polarization. Leakage also contribute polarization, may help explain range polarization values reported in literature....
We show that a thin Gd layer inserted between two thicker layers of permalloy contains an in-plane domain wall whose width can be controlled by varying the thickness layer. The magnetoresistance this structure has been measured with current perpendicular to plane, thus eliminating spurious contributions which have complicated previous measurements. This is first measurement unambiguously contributes additional resistance magnitude in good agreement theory.
The half antivortex, a fundamental topological structure which determines magnetization reversal of submicron magnetic devices with domain walls, has been suggested also to play crucial role in spin torque induced vortex core circular disks. Here, we report on disks nanoholes through consecutive metastable states antivortices. In-plane anisotropic magnetoresistance and broadband susceptibility measurements accompanied by micromagnetic simulations reveal that cobalt (Co) two three linearly...
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,...
Abstract Heating a ferromagnetic material is often perceived as detrimental for most applications. This indeed the case modern nano-scaled spintronic devices which are operated solely (at least ideally) by an electric current. Heat by-product of current-driven operation and it deteriorates many functionalities device. A large scientific technological effort devoted these days to avoid heat in magnetic nano devices. Here we show that can be used provide additional useful degree freedom...
We explore the influence of Fe content on interfacial magnetic properties Ni${}_{1\ensuremath{-}x}$Fe${}_{x}$(50 \AA{})/Fe ($t$ \AA{})/Gd(50 \AA{})/Ni${}_{1\ensuremath{-}x}$Fe${}_{x}$(50 \AA{}) ($x$ $=$ 0.2 and 0.6, $t$ 0 10 multilayers by means element-specific x-ray circular dichroism measurements at Gd M${}_{5}$ (Ni, Fe) L${}_{2,3}$ absorption edges, superconducting quantum interference device magnetometry, specular reflectivity measurements. Increasing in Ni-Fe layer enhances ordering...
The simultaneous determination of magnetoresistance and vectorial-resolved magnetization hysteresis curves in a spin valve structure reveals distinct magnetoresistive features for different magnetic field orientations, which are directly related to the reversal processes. Measurements performed whole angular range demonstrate that response originates from intrinsic anisotropic dependence orientation between two ferromagnetic layers. This also provides direct proof spin-dependent scattering...
We discuss the magnetization processes in sensors based on superposition of a magneto- restrictive amorphous ribbon over piezoelectric plate. These devices show an unusual behavior null condition response curves, which we have related theoretically and experimentally to coercive force magnetic sample changes domain pattern for frequencies near longitudinal resonance frequency.
The main goal of this work is to generate a method control the magnetic properties magnetostrictive metals (anisotropy and coercive field) without affecting total magnetostriction. Multilayers amorphous (Fe80Co20)80B20 are sputtered changing alternatively anisotropy direction successive layers. hysteresis loops show how field can be controlled by playing with thickness ratio Additionally, clear decrease when rotates 90° from layer observed. This effect seems have its origin in mechanical...
In this study, we report a method to optimize the coercivity keeping magnetostriction value constant in electrodeposited CoP multilayers for their applications magnetoelastic magnetic sensors. We have deposited of two different compositions (Co0.74P0.26 and Co0.83P0.17) studied influence thickness layers, total constant. The results show saturation between values materials independent layers. However, reduction layers is accompanied with clear coercive field as low 0.5Oe large increase...