A5050681968- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Magnetic Properties and Applications
- Magnetic Properties of Alloys
- Theoretical and Computational Physics
- Physics of Superconductivity and Magnetism
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Characterization and Applications of Magnetic Nanoparticles
- Quantum and electron transport phenomena
- Magnetic Field Sensors Techniques
- Metallic Glasses and Amorphous Alloys
- Advanced Memory and Neural Computing
- Magneto-Optical Properties and Applications
- Graphene research and applications
- ZnO doping and properties
- Rare-earth and actinide compounds
- Magnetism in coordination complexes
- Surface and Thin Film Phenomena
- Ferroelectric and Negative Capacitance Devices
- Magnetic Properties and Synthesis of Ferrites
- Lanthanide and Transition Metal Complexes
- Monoclonal and Polyclonal Antibodies Research
- Gas Sensing Nanomaterials and Sensors
- Topological Materials and Phenomena
IMDEA Nanoscience
2014-2025
Universidad Autónoma de Madrid
2015-2024
Madrid Institute for Advanced Studies
2015-2024
Instituto de Estudios Avanzados
2020
IMDEA Materials
2017
Centre National de la Recherche Scientifique
2001-2005
Institut Néel
2001-2005
Université Joseph Fourier
2001
Molecular spintronics is a new and emerging sub-area of that can benefit from the achievements obtained in molecular electronics magnetism. The two major trends this area are design analogs inorganic spintronic structures, evolution towards single-molecule spintronics. former trend opens possibility to cheaper devices compatible with plastic technology, while second takes advantage tailor molecules control down single spin. In highlight these will be compared state-of-the-art achieved...
Cu/Co bilayers grown by molecular beam epitaxy on Cu(111) present a peculiar defect: the Cu layers display large fraction of fcc twins, giving rise to lack lateral continuity in film and causing direct ferromagnetic coupling Co/Cu superlattices. We show how formation twins epitaxial can be suppressed precovering clean surface with monolayer Pb that floats at growing film. The use this surfactant results highly improved structural quality
A major challenge for future spintronics is to develop suitable spin transport channels with long lifetime and propagation length. Graphene can meet these requirements, even at room temperature. On the other side, taking advantage of fast motion chiral textures, that is, Néel-type domain walls magnetic skyrmions, satisfy demands high-density data storage, low power consumption, high processing speed. We have engineered epitaxial structures where an ferromagnetic Co layer sandwiched between...
Searching for high-performance permanent magnets components with no limitation in shape and dimensions is highly desired to overcome the present design manufacturing restrictions, which affect efficiency of final devices energy, automotive aerospace sectors. Advanced 3D-printing composite materials related technologies an incipient route achieve functional structures avoiding limitations traditional manufacturing. Gas-atomized MnAlC particles combined polymer have been used this work...
X-ray photoemission electron microscopy (X–PEEM) is a powerful imaging technique that can be used to perform element selective magnetic domain on heterogeneous samples with different layers, like spin valves and tunnel junctions. We have performed nanosecond time-resolved X–PEEM measurements, the permalloy layer of Ni80Fe20 (5 nm)/Cu (10 nm)/Co nm) trilayer deposited Si(111). pump-probe mode, synchronizing pulse from microcoil x-ray photon bunches delivered by BESSY synchrotron in single...
Deposition of Pb on Cu(111) prior to the growth Co/Cu superlattices changes magnetic properties latter. The use a surfactant induces layer-by-layer Co and delays fcc hcp structural transition. As consequence, easy axis magnetization remains perpendicular plane for films grown with Pb. On other hand, elimination twinning in Cu spacers surfactants allows observation complete antiferromagnetic coupling both in-plane out-of-plane magnetization.
We have developed a new original technique to study the magnetization reversal dynamics of thin films with element selectivity in nanosecond time scale. X-ray magnetic circular dichroism measurements pump-probe mode are carried out taking advantage structure synchrotron radiation. The each layers complex heterostructures (like spin valves or tunnel junctions) can be probed independently. interlayer coupling studied systems has been shown play key role determination individual layer.
We present a detailed study on the magnetic properties, including anisotropy, reversal fields, and magnetization processes, of well characterized half-metallic epitaxial La0.7Sr0.3MnO3 (LSMO) thin films grown onto SrTiO3 (STO) substrates with three different surface orientations, i.e. (001), (110) (1-18). The latter shows step edges oriented parallel to [110] (in-plane) crystallographic direction. Room temperature high resolution vectorial Kerr magnetometry measurements have been performed...
We have studied a series of Pt/Co/M epitaxial trilayers, in which Co is sandwiched between Pt and non magnetic layer M (Pt, Ir, Cu, Al). Using polar magneto-optical Kerr microscopy, we show that the field- induced domain wall speeds are strongly dependent on nature top layer, they increase going from M=Pt to lighter metallic overlayers, can reach several 100 m/s for Pt/Co/Al. The DW dynamics consistent with presence chiral N\'eel walls stabilized by interfacial Dzyaloshinskii-Moriya...
Here we report a custom design setup for the simultaneous measurement of magneto-resistance and MOKE imaging in longitudinal configuration characterization magnetic thin-films sensors. The is designed so as to cope with small signal noise ratio initial images allow sensitive magnetoresistance (MR) at low field. An improved differential algorithm used get good enough contrast rid beam illumination or camera gain fluctuations. Home made power supply pre-amplifier stage were reduce frequency...
The ever-increasing demand for efficient data storage and processing has fueled the search novel memory devices. By exploiting spin-to-charge conversion phenomena, spintronics promises faster low power solutions alternative to conventional electronics. In this work, a remarkable 34-fold increase in current is demonstrated when incorporating 2D epitaxial graphene monolayer between iron platinum layers by exploring spin-pumping on-chip Furthermore, it found that spin also anisotropic. This...
An in-plane perpendicular magnetic coupling between Ni80Fe20 and Co has been found in NiFe/NiO/Co trilayers for a NiO thickness ranging from 4 to 25 nm by magneto-optical Kerr effect x-ray circular dichroism measurements. In the easy magnetization direction of layer, coercive field H(C) increases when layer t(NiO) increases. Because coupling, is always larger than NiO/Co bilayers with same thicknesses. The saturation NiFe H(S) decreases increases, indicating weakening coupling. Numerical...
A vectorial magneto-optic Kerr effect (v-MOKE) setup with simultaneous and quantitative determination of the two in-plane magnetization components is described. The provides both polarization rotations reflectivity changes at same time for a given sample orientation respect to variable external magnetic field, as well allowing full angular studies. classical description based on Jones formalism used calculate setup's properties. use different incoming light polarizations and/or MOKE...
This study shows the possibility of dramatically tuning microstructure and magnetic properties gas-atomized Mn54Al46 particles by milling for an unprecedented duration 30 s. flash-milling procedure avoids high temperatures typically achieved in lengthy conventional ball experiments, is efficient to reduce crystallite size nanometer scale, induce microstructural strain ease phase transformations. leads creation τ-MnAl providing magnetization, β-Mn operating mechanism coercivity development....
The design of antiferromagnetic nanomaterials preserving large orbital magnetic moments is important to protect their functionalities against perturbations. Here, we exploit an archetype H6HOTP species for conductive metal-organic frameworks a Co-HOTP one-atom-thick architecture on Au(111) surface. Our multidisciplinary scanning probe microscopy, X-ray absorption spectroscopy, linear dichroism, and circular dichroism study, combined with density functional theory simulations, reveals the...
The crystal structural quality and the strain induced by substrate strictly impose magnetic transport properties of La0.67Sr0.33MnO3 (LSMO) films. In particular, anisotropy (MA) epitaxial LSMO can be finely tuned varying its thickness choosing single substrates with a suitable lattice mismatch film. Here, we have deposited films thicknesses in 12–50 nm range pulsed laser deposition on different inducing either compressive or tensile in-plane manganites. was quantified ω-scans around (002)...
The design of lanthanide multinuclear networks is an emerging field research due to the potential such materials for nanomagnetism, spintronics, and quantum information. Therefore, controlling their electronic magnetic properties paramount importance tailor envisioned functionalities. In this work, a multidisciplinary study presented combining scanning tunneling microscopy, spectroscopy, X-ray absorption linear dichroism, circular density functional theory, multiplet calculations, about...
Current-induced magnetic domain wall motion at zero field is observed in the permalloy layer of a spin-valve-based nanostripe using photoemission electron microscopy. The movement hampered by pinning sites, but between them high velocities (exceeding 150 m/s) are obtained for current densities well below 1012 A/m2, suggesting that these trilayer systems promising applications devices case controlled positions. Vertical spin currents structures provide potential explanation increase velocity...
Synthesis of nanocrystalline Co-ferrite powders with tunable magnetic properties is demonstrated by using co-precipitation and a novel ultrafast milling route.
Abstract The synthesis of lanthanide‐based organometallic sandwich compounds is very appealing regarding their potential for single‐molecule magnetism. Here, it exploited by on‐surface to design unprecedented lanthanide‐directed complexes on Au(111). reported consist Dy or Er atoms sandwiched between partially deprotonated hexahydroxybenzene molecules, thus introducing a distinct family homoleptic sandwiches based six‐membered ring ligands. Their structural, electronic, and magnetic...
Epitaxial graphene/ferromagnetic metal (Gr/FM) heterostructures deposited onto heavy metals have been proposed for the realization of spintronic devices because their perpendicular magnetic anisotropy and sizable Dzyaloshinskii-Moriya interaction (DMI), allowing both enhanced thermal stability stabilization chiral spin textures. However, establishing routes toward this goal requires fundamental understanding microscopic origin unusual properties. Here, we elucidate nature induced spin-orbit...
Dynamic magnetization reversal measurements have revealed a strong dependence of the exchange-coupling strength on maximum applied field for NiO/Co bilayers. Time-resolved Kerr measurements, performed at room temperature, show that coercive increases linearly with between two reversals. If is different in positive and negative directions, an exchange bias observed as well asymmetry behavior sides hysteresis loop. X-ray magnetic circular dichroism Ni ${L}_{2,3}$ edges indicate these effects...
A method for producing self-organised arrays of nanometric metallic dots is reported. It consists on developing first the nanodot pattern by ion erosion a semiconductor cover film and transferring it to previously buried layer. This procedure has been applied Co, ferromagnetic behaviour at room temperature demonstrated.
We have used time-resolved x-ray photoemission electron microscopy to investigate the magnetization dynamics induced by nanosecond current pulses in NiFe/Cu/Co nanostripes. A large tilt of NiFe direction transverse stripe is observed during pulses. show that this effect cannot be quantitatively understood from amplitude Oersted field and shape anisotropy. High-frequency oscillations at onset are attributed precessional motion about effective field. discuss possible origins potential...