A5000859774- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Magneto-Optical Properties and Applications
- Advanced Condensed Matter Physics
- Surface and Thin Film Phenomena
- Magnetic Properties and Applications
- Multiferroics and related materials
- Physics of Superconductivity and Magnetism
- Advanced MEMS and NEMS Technologies
- Magnetic Field Sensors Techniques
- Mechanical and Optical Resonators
- Magnetic Properties and Synthesis of Ferrites
- Shape Memory Alloy Transformations
- Theoretical and Computational Physics
- ZnO doping and properties
- Semiconductor materials and interfaces
- Anodic Oxide Films and Nanostructures
- Electrodeposition and Electroless Coatings
- Magnetic Properties of Alloys
- Acoustic Wave Resonator Technologies
- Rare-earth and actinide compounds
- Photonic Crystals and Applications
- Ferroelectric and Piezoelectric Materials
Universidad de Zaragoza
2014-2024
Instituto de Nanociencia y Materiales de Aragón
2014-2024
Consejo Superior de Investigaciones Científicas
2013-2021
Advanced Institute of Materials Science
2016
Tohoku University
2016
Japan Science and Technology Agency
2016
Fundacion Agencia Aragonesa para la Investigacion y el Desarrollo
2014-2015
Instituto Nacional de Técnica Aeroespacial
2010
Leibniz Institute for Solid State and Materials Research
2010
Universidad Complutense de Madrid
2004-2007
We report the first experimental observation of spin Seebeck effect in magnetite thin films. The signal observed at temperatures above Verwey transition is a contribution from both anomalous Nernst (ANE) and effects (SSE). ANE Fe3O4 layer to SSE found be negligible due resistivity difference between Pt layers. Below free ferromagnetic it also dominate over magnetic proximity on layer.
We report a complete characterization of the anomalous Nernst effect (ANE) and its relationship with Hall (AHE) in ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$. By combining full thermoelectric electric transport measurements as function temperature, we have verified that universal scaling relation between diagonal conductivities (${\ensuremath{\sigma}}_{zy}\ensuremath{\propto}{\ensuremath{\sigma}}_{zz}^{1.6}$), observed materials bad-metal-hopping type conduction, is also applicable to transport....
Thermal spin pumping constitutes a novel mechanism for generation of currents; however their weak intensity major roadblock its usefulness. We report phenomenon that produces huge current in the central region multilayer system, resulting giant Seebeck effect structure formed by repetition ferromagnet/metal bilayers. The result is consequence interconversion magnon and electron currents at multiple interfaces. This work opens possibility to design thin film heterostructures may boost...
Terahertz emission spectroscopy of ultrathin multilayers magnetic and heavy metals has recently attracted much interest. This method not only provides fundamental insights into photoinduced spin transport spin-orbit interaction at highest frequencies but also paved the way to applications such as efficient ultrabroadband emitters terahertz electromagnetic radiation. So far, predominantly standard ferromagnetic materials have been exploited. Here, by introducing a suitable figure merit, we...
We show here that using spin orbit coupling interactions at a metallic interface it is possible to control the sign of charge conversion in pumping experiment. Using intrinsic symmetry “Inverse Rashba Edelstein Effect” (IREE) Bi/Ag interface, current changes when reversing order Ag and Bi stacking. This confirms IREE nature into these interfaces opens way tailoring sensing voltage by an appropriate trilayer sequence.
The biaxially textured growth of superconducting Co-doped BaFe2As2 (Ba-122) thin films has been realized on ion beam assisted deposition (IBAD) MgO coated conductor templates by employing an iron buffer architecture. pnictide showed a transition temperature 21.5 K, which is slightly lower than that Ba-122 single crystalline substrates. A self-field critical current density over 105 A·cm-2 already achieved even at 8 K. experiment highlights the potential possible applications iron-based...
This work reports the fabrication and characterization of Langmuir–Blodgett films nanoparticles (size 51 ± 10 nm) metal organic framework MIL-101(Cr). LB film by SEM, UV–vis, GIXRD, QCM has shown that addition 1 wt % behenic acid to MOF dispersion allows obtaining dense monolayers at air–water interface can be deposited onto solid substrates different nature with transfer ratios close 1. Moreover, a QCM-based setup been built used for first time measure CO2 adsorption isotherms 303 K on...
Spin transport is crucial for future spintronic devices operating at bandwidths up to the terahertz (THz) range. In F|N thin-film stacks made of a ferro/ferrimagnetic layer F and normal-metal N, spin mediated by (1) spin-polarized conduction electrons and/or (2) torque between electron spins. To identify cross-over from (2), we study laser-driven currents in F|Pt where consists model materials with different degrees electrical conductivity. For magnetic insulators YIG, GIG maghemite,...
The spin Peltier effect (SPE), heat-current generation as a result of spin-current injection, has been investigated in alternately stacked Pt/${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ multilayer films. temperature modulation induced by the SPE $[\text{Pt}/{\mathrm{Fe}}_{3}{\mathrm{O}}_{4}]\ifmmode\times\else\texttimes\fi{}n$ films was found to be significantly enhanced with increasing number bilayers $n$. This enhancement is much greater than that expected for simple stack independent bilayers....
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...
Epitaxial strain alters the physical properties of thin films grown on single crystal substrates. Thin film oxides are particularly apt for engineering new functionalities in ferroic materials. In case La(2/3)Ca(1/3)MnO(3) (LCMO) films, here we show first experimental images obtained by electron holography demonstrating that epitaxial induces segregation a flat and uniform nonferromagnetic layer with antiferromagnetic (AFM) character at top surface ferromagnetic (FM) layer, whole being...
We report a systematic study on the thermoelectric performance of spin Seebeck devices based Fe3O4/Pt junction systems. explore two types device geometries: Hall thermopile and multilayer structures. The increases sensitivity effect, while increase in sample internal resistance has detrimental effect output power. found that multilayers can overcome this limitation since exhibit enhancement voltage reduction simultaneously, therefore resulting significant power enhancement. This result...
We report the fabrication of high crystal quality epitaxial thin films maghemite (γ−Fe2O3), a classic ferrimagnetic insulating iron oxide. Spin Seebeck effect (SSE) measurements in γ−Fe2O3/Pt bilayers as function sample preparation conditions and temperature yield SSE coefficient 0.5(1) μV/K at room temperature. Dependence on allows us to estimate magnon diffusion length be range tens nanometers, good agreement with that conducting oxide magnetite (Fe3O4), establishing relevance spin...
The dependence of Spin Seebeck effect (SSE) with the thickness magnetic materials is studied by means incoherent thermal excitation. SSE voltage signal in Fe3O4/Pt bilayer structure increases material up to 100 nm, approximately, showing signs saturation for larger thickness. This well described terms a spin current pumped platinum film magnon accumulation material. generated gradient temperature system and detected Pt top contact inverse Hall effect. Calculations frame linear response...
We report the effect of interface symmetry-mismatch on magnetic properties LaCoO3 (LCO) thin films. Growing epitaxial LCO under tensile strain top cubic SrTiO3 (STO) produces a contraction along c axis and characteristic ferromagnetic response. However, we here that ferromagnetism in is completely suppressed when grown buffer layer rhombohedral La2/3Sr1/3MnO3 (LSMO), spite identical in-plane out-of-plane lattice deformation. This confirms it symmetry mismatch not just total strain, which...
Abstract Reversible structural transformations between perovskite (PV) ABO 3− δ and brownmillerite (BM) 2.5 (A = Ca 2+ , Sr ; B Fe 4+/3 Co 4+/3+ ) oxides can be induced by topotactic oxygen exchange at moderate temperatures under reducing/oxidizing conditions. The combination of a large oxide‐ion conductivity small free energy difference the oxidation states many 3d transition metal ions enables these transformations. Herein, it is demonstrated that electric field produced voltage‐biased...
We report the disentanglement of bulk and interfacial contributions to thermally excited magnon spin current in Seebeck effect under static heating. For this purpose, we have studied dependence inverse Hall voltage thermal conductivity on magnetic layer thickness. Knowledge these quantities allows us take into account influence both sources analysis dependence. The thickness modulates relative magnitude involved drops for a fixed total difference throughout sample. In end, attain separate...
We report temperature dependent measurements of the spin Seebeck effect (SSE) in multilayers formed by repeated growth a Fe3O4/Pt bilayer junction. The magnitude observed enhancement SSE, relative to SSE single bilayer, shows monotonic increase with decreasing temperature. This result can be understood an characteristic length for current transport system, qualitative agreement recently magnon diffusion Fe3O4 at lower temperatures. Our suggests that thermoelectric performance multilayer...
Spin Hall and Rashba–Edelstein effects, which are spin-to-charge conversion phenomena due to spin–orbit coupling (SOC), attracting increasing interest as pathways manage rapidly at low consumption cost the storage processing of a large amount data in spintronic devices well more efficient energy harvesting by spin-caloritronics devices. Materials with SOC, such heavy metals (HMs), traditionally employed get conversion. More recently, use graphene (gr) proximity SOC layers has been proposed...
Cubic Yttrium Iron Garnet (YIG) is a technologically important material due to its excellent magneto-optical properties, high electrical resistivity, and very narrow ferromagnetic resonance, which makes it particularly suitable for applications in filters resonators at microwave frequencies. These properties depend on the precise stoichiometry distribution of Fe${}^{3+}$ ions among octahedral/tetrahedral sites complex structure, required use high-vacuum deposition methods fabrication...
In the last few years, magnetic nanowires have gained attention due to their potential implementation as building blocks in spintronics applications and, particular, domain-wall- based devices. these devices, control of properties is a must. Cylindrical can be synthesized rather easily by electrodeposition and achieved modulating composition nanowire along axial direction. this work, we report possibility introducing changes radial direction, increasing degrees freedom harness magnetization....
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...
Oxide spinels of general formula AB2O4 (A = Mg2+, Fe2+; B Al3+, Cr3+, etc.) constitute one the most abundant crystalline structures in mineralogy. In this structure, cations distribute among octahedral and tetrahedral sites, according to their size crystal-field stabilization energy. The cationic arrangement determines mechanical, magnetic, transport properties spinel can be influenced by external parameters like temperature, pressure, or epitaxial stress case thin films. Here, we report a...
We have studied the anomalous Nernst effect (ANE) in [Fe3O4/Pt]-based heterostructures grown at high temperature, by measuring ANE-induced electric field with a magnetic applied normal to sample surface, perpendicular magnetized configuration, where only ANEs from ferromagnetic layers or proximity effects can be detected. An ANE voltage is observed for [Fe3O4/Pt]n multilayers, and we further investigated its origin performing measurements [Fe3O4/Pt/Fe3O4] trilayers as function of Pt...