Artículos (Física Aplicada I)

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Glide Symmetry Can Be Key to Enhance the Performance of Periodicity-Based Microwave Bandstop Filters
(Institute of Electrical and Electronics Engineers (IEEE), 2025-06-25) Fernández Prieto, Armando; Mesa Ledesma, Francisco Luis; Martel Villagrán, Jesús; Quevedo-Teruel, Óscar; Medina Mena, Francisco; Electrónica y Electromagnetismo; Física Aplicada I; Física Aplicada II; Ministerio de Ciencia, Innovación y Universidades (MICIU). España
Higher-order symmetries are essential in physics and electromagnetism, providing insights into the fundamental principles that govern a great variety of physical phenomena. Beyond their theoretical importance, these symmetries bring practical advantages, simplifying complex calculations and enhancing the design and functionality of numerous technological applications. This article investigates the recent application of higher-order symmetries, particularly glide symmetry, in the design of planar microwave circuits, with a focus on common-mode rejection filters. By reviewing recent advancements and applications, we aim to underscore the potential of these advanced symmetries to significantly enhance the performance and versatility of micro-wave planar circuits, as well as to inspire further research and innovation within this field.
Formation and Coherent Propagation of Femtosecond-Laser-Induced Periodic Surface Structures (LIPSS) in Fluorine-Doped Tin Oxide: Control, Potential Applications, and Challenges
(American Chemical Society (ACS), 2026-06-22) Gómez-Munoz, Gonzalo; Ariza, Rocío; Núñez Gálvez, Fernando; López Flores, Víctor; Cabello-Pardos, Fátima; Sotillo, Belén; Prieto, Carlos; García López, Francisco Javier; López Santos, Carmen; Solís, Javier; Física Aplicada I; Física Atómica, Molecular y Nuclear; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España; Comunidad Autónoma de Madrid
We have analyzed the formation and coherent propagation of laserinduced periodic surfa cestructures (LIPSS) upon fs-laser irradiation of fluorine-doped tin oxide (FTO) films. The aim is the generation of large electrical anisotropies in macroscopic áreas for applications including laser-written transparent heaters, sensors, or substrates for electrically controlable wettability, among others. The films have been processed with high-repetition-rate (hundreds of kHz) fs-laser pulses at 1030nm using different laser (fluence and pulse duration) and scanning parameters (speedand line overlap). Optimal LIPSS formation and coherent propagation are conditioned by the dynamic evolution of the F content in the laser-processed regions that can be controlled via processing parameters. However, the homogeneity in the spatial distribution of F in the microscale in the pristine samples can generate important issues that are carefully considered and discussed in the present work. Still, the formation of optically and electrically highly anisotropic surfaces for laser scanning speeds well above 1.0m/s has been demonstrated, reaching electrical resistivity anisotropy factors of > 103. Consequently, the large-area applications using LIPSS-structured FTO films seems feasible, as we have demonstrated by fabricating an efficient laser-written electrothermal transparent device as a proof-of-concept.
Charge transport in single crystal CVD diamond studied at high temperatures
(IOP Publishing LTD, 2021) Crnjac, Andreo; Rodríguez Ramos, Mauricio; Skukan, Natko; Pomorski, Michal; Jaksic, Milko; Física Aplicada I; RNM138: Física Nuclear Aplicada
The capability of single crystal diamonds to maintain their unique electronic properties even at high temperatures is, in particular, relevant for its applications as a radiation detector. In order to explore characteristics of charge transport at high temperatures (up to 450 ◦C), diamond was exposed to MeV energy ions, both, to induce radiation damage and to probe subsequent influence on detector’s properties. Dependence of mobility-lifetime product with temperature has been obtained for electrons and holes. For holes, mu-tau displays a linear degradation with rising temperature, while for electrons, change with temperature is less evident. Furthermore, deep trapping levels induced in the material by radiation damage, were studied through time-resolved charge signals. Detrapping time was extracted from this data. Hole trap level, with the activation energy of 0.53 ± 0.01 eV has been detected in the regions of the diamond detector previously irradiated by 5 MeV damaging proton beam, but not in the pristine regions. This indicates that the trap was formed due to defect induction during radiation damage exposure. Activation of this deep level is important for charge transport performance in diamond detectors operating at high temperatures and high radiation conditions.
Ion Microprobe Study of the Polarization Quenching Techniques in Single Crystal Diamond Radiation Detectors
(MDPI, 2022) Rodríguez Ramos, Mauricio; Crnjac, Andreo; Cosic, Donny; Jaksic, Milko; Física Aplicada I; RNM138: Física Nuclear Aplicada
Synthetic single crystal diamond grown using the chemical vapor deposition technique constitutes an extraordinary candidate material for monitoring radiation in extreme environments. However, under certain conditions, a progressive creation of space charge regions within the crystal can lead to the deterioration of charge collection efficiency. This phenomenon is called polarization and represents one of the major drawbacks associated with using this type of device. In this study, we explore different techniques to mitigate the degradation of signal due to polarization. For this purpose, two different diamond detectors are characterized by the ion beam-induced charge technique using a nuclear microprobe, which utilizes MeV energy ions of different penetration depths to probe charge transport in the detectors. The effect of polarization is analyzed by turning off the bias applied to the detector during continuous or discontinuous irradiation, and also by alternating bias polarity. In addition, the beneficial influence of temperature for reducing the effect of polarization is also observed. Finally, the effect of illuminating the detector with light is also measured. Our experimental results indicate that heating a detector or turning off the bias, and then applying it during continuous irradiation can be used as satisfactory methods for recovering the CCE value close to that of a prepolarized state. In damaged regions, illumination with white light can be used as a standard method to suppress the strength of polarization induced by holes.
Non-equilibrium attractor for non-linear stochastic dynamics
(EPL Association, 2024-02-07) Patrón Castro, Antonio; Sánchez-Rey, Bernardo; Trizac, E.; Prados Montaño, Antonio; Física Atómica, Molecular y Nuclear; Física Aplicada I; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Union (UE); Junta de Andalucía
We study the dynamical behaviour of mesoscopic systems in contact with a thermal bath, described either via a non-linear Langevin equation at the trajectory level—or the corresponding Fokker-Planck equation for the probability distribution function at the ensemble level. Our focus is put on one-dimensional—or d-dimensional isotropic—systems in confining potentials, with detailed balance—fluctuation- dissipation thus holds, and the stationary probability distribution has the canonical form at the bath temperature. When quenching the bath temperatura to low enough values, a far-from-equilibrium state emerges that rules the dynamics over a characteristic intermediate time scale.S uch along-lived state has a Dirac-delta probability distribution function and attracts all solutions over this intermediate time scale, in which the initial conditions are inmaterial while the influence of the bath is still negligible. Numerical evidence and qualitative physical argumentss uggest that the above picture extends to higher-dimensional systems, with anisotropy and interactions.
Kinetic glass transition in granular gases and nonlinear molecular fluids
(American Physical Society, 2024-04-16) Patrón Castro, Antonio; Sánchez-Rey, Bernardo; Prados Montaño, Antonio; Física Atómica, Molecular y Nuclear; Física Aplicada I; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Union (UE); Junta de Andalucía
In this paper we investigate, both analytically and numerically, the emergence of a kinetic glass transition in two different model systems: a uniformly heated granular gas and a molecular fluid with nonlinear drag. Despite the profound differences between these two physical systems, their behavior in thermal cycles share strong similarities, which stem from the relaxation time diverging algebraically at low temperatures for both systems. When the driving intensity—-for the granular gas—or the bath temperature—for the molecular fluid— is decreased to sufficiently low values, the kinetic temperature of both systems becomes “frozen" at a value that depends on the cooling rate through a power law with the same exponent. Interestingly, this frozen glassy state is universal in the following sense: for a suitable rescaling of the relevant variables, its velocity distribution function becomes independent of the cooling rate. Upon reheating, i.e., when either the driving intensity or the bath temperature is increased from this frozen state, hysteresis cycles arise and the apparent heat capacity displays a maximum. The numerical results obtained from the simulations are well described by a perturbative approach.
Ion Microbeam Studies of Charge Transport in Semiconductor Radiation Detectors With Three-Dimensional Structures: An Example of LGAD
(Frontiers Media SA, 2022) Jaksic, Milko; Crnjac, Andreo; Kramberger, Gregor; Manojlovic, Miloš; Lastovicka-Medin, Gordana; Rodríguez Ramos, Mauricio; Física Aplicada I; RNM138: Física Nuclear Aplicada
The development of semiconductor detectors with an increased tolerance to high radiation levels often results in devices that deviate significantly from those of the classical design with planar electrodes. Decreasing the charge drift distance and/or introducing localised charge multiplication volumes are two detector development strategies that are often used in an attempt to increase the device radiation hardness. However, such approaches result in a more complex three-dimensional distribution of electrodes and sensitive detector volumes, which presents a challenge for the microscopic characterisation of charge transport properties. IBIC (ion beam-induced charge) is one of the available microscopic characterisation techniques that utilises focused, MeV energy range ions to probe charge transport. Here we used IBIC to probe different detector depths by varying the ion energy and/or angle of incidence and to probe certain detector regions by ions of the same range but with different stopping powers. These investigations are particularly important for studying low gain avalanche diode (LGAD) detectors, where measured interpad distances change with proton energy and where an increased carrier density results in changes in the charge multiplication, which are studied in this work.
The influence of multiple ionization and chemical effects on magnesium Kα X-ray spectra in high-resolution proton and alpha PIXE measurements
(Royal Soc Chemistry, 2026) Miokovic, Anja; Mihalic, Iva Božičević; Fazinic, Stjepko; Rodríguez Ramos, Mauricio; Física Aplicada I; RNM138: Física Nuclear Aplicada
High-resolution wavelength-dispersive (WD) X-ray emission spectra of the Mg Ka band were measured for metallic Mg and selected Mg compounds under excitation with 2–3 MeV proton (H) and 1.5–5 MeV alpha (He) ion beams. The study investigated the influence of chemical state as well as ion beam type and energy on the positions and relative intensities of Mg Ka spectral line components. In addition to the characteristic X-ray emission line, H-induced spectra revealed KL1 multiple ionization satellite (MIS) lines, while He excitation produced both KL1 and KL2 MIS groups with strong energy-dependent relative intensities. Small but measurable peaks' energy shifts were observed among different Mg compounds. Statistically significant variations in the relative intensities of KL1 group's components, correlating with chemical bonding, were also detected. The use of He excitation resulted in enhanced sensitivity for chemical speciation.
Simulating 241Pu, 241Am and 237Np transport released from a nuclear fuel reprocessing plant in the European Shelf Seas and their fluxes into the Arctic
(Elsevier, 2026-06) Cortés Parejo, María del Carmen; Periáñez Rodríguez, Raúl; Matemática Aplicada I; Física Aplicada I; FQM164: Matemática Discreta: Teoría de Grafos y Geometría Computacional; RNM138: Física Nuclear Aplicada
A three-dimensional Lagrangian particle-tracking model has been applied to simulate the dispersion, sediment interactions and radioactive decay of 241Pu, 241Am and 237Np released from the Sellafield nuclear fuel reprocessing plant into the European Shelf Seas over the period 1952–2014. The model incorporates advection by currents, turbulent diffusion, reversible sediment-water exchanges and the explicit representation of the 241Pu→ 241Am→ 237Np decay chain. Simulated concentrations in surface waters and bottom sediments are compared with available measurements in the Irish Sea, North Sea and adjacent regions, reproducing the contrasting environmental behaviours of the three radionuclides. Results highlight the strong sediment retention of 241Am and 241Pu, whereas 237Np exhibits a more conservative behaviour and wider dispersal. Fluxes into the Arctic Ocean through the Norwegian Coastal Current are quantified, yielding cumulative exports of 2.07 × 1014 Bq for 241Pu and 1.43 × 1014 Bq for 237Np, and suggesting an average transit time of approximately 10 years for 241Pu from Sellafield to the Arctic boundary. Basin-scale inventories in water and sediments are also estimated, revealing the dominant role of sediments as long-term sinks for particlereactive radionuclides. The results demonstrate the capability of the modelling framework to provide internally consistent multi-decadal inventories and fluxes for complex radioactive decay chains in shelf-sea environments.
Fully Metallic Dual-Band Linear-to-Circular Polarizer for K/Ka-band
(IEEE-INST Electrical Electronics Engineers INC, 2021) Lundgren, Johan; Zetterstrom, Oskar; Mesa Ledesma, Francisco Luis; Fonseca, Nelson J.G.; Quevedo-Teruel, Óscar; Física Aplicada I; TIC112: Microondas
A dual-band polarizer is presented that converts linear polarization into circular polarization with orthogonal handedness in the satcom bands 19.7–20.2 GHz and 29.5–30 GHz. The polarizer consists of three identical cascaded perforated metallic screens, whose perforations are periodically repeated crosses of two sizes. Unlike previously reported dual-band polarizers, our design is fully metallic, which results in low losses and makes it suitable for space applications. A prototype of the polarizer with 20 × 20 unit cells is manufactured, and the measurement results agree well with the simulated results. In the nominal satcom bands, the measured axial ratio and the insertion loss are better than 1.7 and 0.67 dB. In the bands 18.9–20.3 GHz and 29.1–30.1 GHz, the measured axial ratio and insertion loss are below 3 and 1 dB.
Wideband Quasi-Nondiffracting Radial GRIN Lenses
(Electrical Electronics Engineers INC, 2026) Chen, Mingzheng; Comite, Davide; León, Germán; Mesa Ledesma, Francisco Luis; Quevedo Teruel, Óscar; Física Aplicada I; TIC112: Microondas
We propose a quasi-closed-form refractive index profile for flat radial gradient index (GRIN) lenses that allows the generation of direction-steerable quasi-nondiffracting beams in a wide frequency range. The GRIN profile is derived so that the optical path lengths of rays reaching the lens aperture are linearly correlated, leading to the generation of quasi-nondiffracting beams within a rhombic region near the lens. Detailed phase error analysis demonstrates that the proposed formulation is valid for a wide range of GRIN lens parameters, including the maximum refractive index, the specified maximum edge phase (which determines the nondiffracting range of the lens), the focal distance, and the thickness of the lens. The validation of the proposed GRIN profile is tested by both full-wave simulations and measurements of a 3-D printed prototype. Experimental results reveal that the designed GRIN lens generates a 2-D scanning quasi-nondiffracting beam with a scanning range of ±25.6◦ in elevation angle and full azimuth coverage from 26 to 40 GHz, spanning the entire Ka-band.
Controlled grain-size thermochromic VO2 coatings by the fast oxidation of sputtered vanadium or vanadium oxide films deposited at glancing angles
(Elsevier, 2021) Santos, Antonio J.; Lacroix, Bertrand; Berrocoso Domínguez, Manuel; García, Rafael; Martín, Nicolás; Morales, Francisco Miguel; Física Aplicada I; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
An original, simple and cost-effective oxidation strategy to attain thermochromic vanadium dioxide thin films is reported. This two-step procedure comprises the initial deposition of DC magnetron-sputtered vanadium or vanadium oxide films by the combination of glancing angle deposition and, if needed, reactive gas pulsing process, followed by fast oxidation of such layers in air atmosphere at high temperatures. Thanks to the careful control of the thermal treatment parameters, and taking advantage of the superior reactivity of the high surface- to-volume porous deposited structures, the formation of pure VO2 (M1) layers was achieved. The comprehensive characterization of such oxidized systems by means of scanning electron microscopy, Raman spectroscopy and scanning-transmission electron microscopy techniques such as electron energy-loss spectroscopy, not only confirmed the presence of the VO2 (M1) phase, but also allowed to shed light on the key role that reaction time plays in the selective formation of vanadium dioxide films of adjustable grain size and crystallinity. The optimal conditions to stabilize thermochromic VO2 consists in using large deposition angles (85 ◦) and short oxygen pulses (≤2 s) during the growth, followed by fast and short thermal treatments (≤45 s with a heating rate of 42 ◦C s 1) in air atmosphere at 550 ◦C. The metal-to-insulator response of the accomplished VO2 layers was finally evaluated by means of temperature dependent Kelvin probe force microscopy measurements, evidencing surface potential drops at heating, greater than those reported in the literature to date for VO2 thin films.
Texture in ITO films deposited at oblique incidence by ion beam sputtering
(Elsevier, 2022) Lacroix, Bertrand; Paumier, Fabien; Santos, Antonio J; Maudet, Florian; Girardeau, Thierry; Dupeyrat, Cyril; García, Rafael; Morales, Francisco Miguel; Física Aplicada I; Ministerio de Ciencia, Innovación y Universidades (MICIU). España
Texture of crystalline In2O3:Sn (ITO) thin films prepared by combining ion beam sputtering (IBS) at room temperature and oblique angle deposition (OAD) has been studied depending on the vapor incidence on Si substrates (𝛼, ranging from 50◦ to 85◦) and the ions used to sputter the target (argon or xenon accelerated at 1.2 keV). Films obtained using Xe ions show an unusual evolution depending on the deposition angle 𝛼, with the development of a dual biaxial (111) off-axis texture for 𝛼 ≤ 70◦, and a switching in the preferred out-of-plane orientation from [111] to [001] for 𝛼 > 70◦ that leads to a biaxial (001) texture at highest deposition angles. These behaviors are well described by mechanisms involving a maximization of the direct capture of the adatoms on {111} planes, which can however be hindered when mobilities are exalted such as in the case of Ar deposition. The tuning of adatoms mobilities through the IBS process mixed with the control of the deposition angle offered by the OAD geometry appears as an efficient route to achieve an upgraded texture engineering in nanostructured ITO thin films.
Application of advanced (S)TEM methods for the study of nanostructured porous functional surfaces: A few working examples
(Elsevier, 2022) Santos, Antonio J; Lacroix, Bertrand; Maudet, Florian; Paumier, Fabien; Hurand, Simon; Dupeyrat, Cyril; Gómez, Víctor J.; Huffaker, Diana. L; Girardeau, Thierry; García Roja, Edwin. R; Morales, Francisco Miguel; Física Aplicada I
Nanostructured films offer the ability of modifying surface properties, even more, when they can generate layers with controlled porosity. The lower implicit integrity of these (multi)layers when compared to their compact counterparts, hinders the attainment of electron-transparent sections of submicron thicknesses (lamellae), which becomes one of the main reason for the scarcity of studies thorough (scanning-)transmission electron microscopy ((S)TEM). Aware of this opportunity, this report provides an overview of the possibilities offered by the application of a variety of (S)TEM techniques for the study of nanostructured and porous photonic surfaces. A few working examples are presented to illustrate the type of information that can be obtained in the case of mesoporous films prepared either by at oblique angles physical processes as well as nitride nanowire arrays prepared by epitaxy methods. It will be demonstrated that this approach enables the realization of several pioneering works, which are essential to complete the characterization of such porosity-controlled coatings. Topics as diverse as the preparation of electron-transparent specimens and the advanced characterization of their structures, morphologies, interfaces and compositions are addressed thanks to the implementation of new breakthroughs in (S)TEM, which allow to obtain high-resolution imaging, spectroscopies, or tomography, at both microscopic and nanoscopic levels. Finally, establishing (S)TEM as a reference tool for the advanced structural, chemical and morphological characterization of porous nanostructured skins, will open new horizons, providing better and new insights and thus allowing the optimization of the fabrication and design of such architectures.
Unveiling single-electron tunneling in nanogranular ultrathin films for sensor applications via hyperspectral conductive AFM
(Elsevier, 2025) Bakkali Azlou, Hicham; Berrocoso Domínguez, Manuel; Física Aplicada I; Ministerio de Ciencia, Innovación y Universidades (MICIU). España
This study maps the electrical behavior across a 7 × 7 μm2 nanogranular ultrathin Pd-ZrO2 film, revealingnonlinear I-V characteristics indicative of single-electron tunneling. Following the Coulomb blockade power lawI ~ (V 􀀀 Vt)ξ with a scaling exponent ξ ≈ 1.2, these characteristics appear above the threshold voltage Vt. Bymodeling the nanogranular structure as a 1D array of multitunnel junctions, we demonstrate a linear relationshipbetween Vt and tunnel channel length, allowing for a better understanding of nanoscale electrical properties andsupporting the development of sensitive sensors.
Influence of near-edge Laser-Induced Periodic Surface Structures (LIPSS) on the electrical properties of fs-laser-machined ITO microcircuits
(Elsevier, 2026-06-15) Frechilla Zabal, Alejandro; Martínez Fernández, Elena; Moral, Jaime del; López Santos, Carmen; Frechilla Zabal, Javier; Núñez Gálvez, Fernando; López Flores, Víctor; Fuente, Germán F. de la; Hülagü, Deniz; Bonse, Jörn; González-Elipe, Agustín R.; Borrás Martos, Ana Isabel; Angurel Lambán, Luis Alberto; Física Aplicada I; European Union (UE). H2020; Ministerio de Ciencia e Innovación (MICIN). España; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); FQM196: Nanotecnología en Superficies y Plasma
Scalable, cost-effective methods for processing transparent electrodes at the microscale are pivotal to advancing in electrochemistry, optoelectronics, microfluidics, and energy harvesting. In these fields, the precise fabrication of micrometric circuits and patterns plays a critical role in determining device performance, material compatibility, and integration with added-value substrates. In this context, Laser Subtractive Manufacturing stands out as a suitable microfabrication technique for its adaptability to diverse materials and complex configurations, as well as its straightforward scalability, affordability, and eco-friendly nature. However, a challenge in micromachining metals and metal oxides is the inherent formation of Laser-Induced Periodic Surface Structures (LIPSS), which can significantly impair electrical conductivity, particularly when circuit dimensions fall within the micrometer range. Herein, we investigate the micromachining of electrical microcircuits using ultrashort pulse laser systems applied to transparent indium tin oxide (ITO) thin films. We analyze the formation of LIPSS at the edges of the micromachined regions associated with the Gaussian distribution of the energy within the laser spot, and the impact of these structures on the electrical properties of the circuits. Thus, we systematically evaluate the influence of LIPSS orientation and periodicity by fabricating various circuit patterns using femtosecond lasers at green (515 nm) and ultraviolet (UV) (343 nm) wavelengths. A correlation between electrical resistivity measurements and microstructure analysis, as determined by field emission scanning electron and transmission electron microscopy, reveals distinct effects of the formed nanostructures depending on the laser source and its polarization. For the green wavelength, the edge side regions where LIPSS are oriented perpendicular to the ITO track exhibit a resistance higher by a factor just above two compared to those where LIPSS are parallel. Additionally, UV laser processing results in a pronounced reduction of ITO thickness at the boundary between the LIPSS region and the substrate. The mechanisms for the formation of LIPSS with both wavelengths are also discussed. Furthermore, we have determined that in narrow conductive tracks with a width ranging from 6 to 8 µm, the impact of LIPSS is particularly significant because the LIPSS structured region occupies a dominant fraction of the total width.
Voids and nanopores in nanocolumnar platinum thin films grown by magnetron sputtering and evaporation at oblique angles: A comparative analysis
(Elsevier, 2025) García Valenzuela, Augusto; Acosta Rivera, Hiedra; Oskar Liedke, Maciej; Butterling, Maik; Hirschmann, Eric; Attallah, Ahmed G.; Wagner, Andreas; Rojas, T. C.; Álvarez Molina, Rafael; Rico-Gavira, Víctor Joaquín; Palmero, Alberto; Rodríguez González-Elipe, Agustín; Física Aplicada I; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; FQM196: Nanotecnología en Superficies y Plasma
Nanocolumnar thin films deposited at oblique angle (OA) by magnetron sputtering or evaporation often show common structural aspects when grown under equivalent geometrical conditions. This is the case of the column tilt angle as a function of the geometrical deposition arrangement, which coincides for some materials no matter the technique. This feature has usually been taken as a sign of a common type of growth, even though no other morphological aspects have been systematically compared. In this paper, a comparison between nanocolumnar Pt thin films grown at OA by evaporation and magnetron sputtering has been carried out, demonstrating the existence of profound differences in film density, columnar width or preferential crystalline texture, despite exhibiting the same nanocolumnar tilt. Moreover, the size distribution of voids and nanopores embedded in the nanocolumns has been specifically analyzed by means of two Positron Annihilation Spectroscopy techniques, demonstrating the existence of large variations depending on the preparation method. With the help of a growth model, these differences are discussed under the light of the atomistic processes present in evaporation and magnetron sputtering and, more specifically, on mobility processes triggered by the arrival of deposition atoms with relatively high kinetic energy.
Acoustic wave-powered durable icephobic duplex coating design with superior deicing performance
(American Chemical Society, 2026) Moral Jalón, Jaime del; Haworth, Luke; Montes Montañez, Laura; Sánchez Valencia, Juan Ramón; Barranco Quero, Ángel; Rico Gavira, Victor Joaquin; Czermak, Triana; Carreño Puertas, Francisco; García Gallego, Paloma; Mora Nogués, Julio; López Santos, Carmen; Winkler, Andreas; Borrás Martos, Ana Isabel; Rodríguez González-Elipe, Agustín; Fu, Yongqing; Física Aplicada I; Agencia Estatal de Investigación. España; European Union (UE). H2020; Consejo Superior de Investigaciones Científicas (CSIC)
Piezoelectric thin film-based surface acoustic wave (SAW) deicing technology has recently emerged as an attractive and energy-efficient alternative with direct applications across multiple industrial sectors. However, the generation of SAWs on piezoelectric thin films, such as ZnO, faces diverse challenges, including its low long-term stability and variable wetting properties upon exposure to UV radiation and other environmental hazards. To overcome these challenges, we propose a bilayer coating design that integrates a diamond-like carbon (DLC) thin film with an atop CFx layer (DLC-CFx). This design is intended to serve as both an anti-icing and a protective coating for ZnO SAW devices built on aluminum substrates, which are specifically selected for critical ice-exposed applications in the aeronautics or wind turbine industries. We demonstrate that, unlike the implementation of single fluorinated polymer layers, such as commercial CYTOP, the DLC-CFx hydrophobic duplex coating effectively protects the ZnO surfaces while maintaining optimal SAW transmission and wave propagation and reducing the fluorine content. The SAW-induced deicing on these devices is achieved through a highly effective mechanism involving the interfacial ice melting, followed by a rapid ice sliding detachment for both small ice droplets and large ice aggregates. Experiments at laboratory scale and in an icing wind tunnel facility reveal that deicing involves SAW activation of the interface between the ice and the DLC-CFx bilayer, as well as an effective thermal contribution resulting from the rapid heat transmission through the aluminum substrate. Our studies demonstrate that the highly conformal deposition of DLC-CFx through a room temperature plasma-assisted method ensures reliability and long-term stability of thin-film-based acoustic wave devices in harsh outdoor conditions.
Characterization of a 100 nm RADFET as a proton beam detector
(MDPI, 2025-12-27) Moreno Pérez, Juan Antonio; Ruiz García, Isidoro; Duane, Russell; Martín Holgado, Pedro; Morvaj, Ljiljana; Vasovic, Nikola; Hajdas, Wojtek; Morilla García, Yolanda; Carvajal Rodríguez, Miguel Ángel; Física Aplicada I; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER)
The RADFET VT06 developed by Varadis (Cork, Ireland), which is aimed at high-dose applications, mainly for spacecraft missions, has been characterized by low- and high-energy proton beams at two different facilities, the Accelerator National Centre (Sevilla, Spain) and the Paul Scherrer Institute (PSI) located in Villigen (Switzerland), using a reader unit system developed by the University of Granada (Spain). The devices have been characterized with proton energies of 1, 2, 3, 150, and 230 MeV, with accumulated doses from 130 to 512 Gy, where the RADFET was unbiased during the irradiation while the source voltage was measured before and after irradiation to monitor the radiation dose. Excellent linearity has been obtained with a minimum correlation factor R2 of 0.996, with a sensitivity that can vary from (0.691 ± 0.007) mV/Gy for 1 MeV to (1.143 ± 0.023) mV/Gy for 230 MeV without any build-up layer. An excellent stability was found in the studied cases, with dispersion being lower than 4% after a dose accumulation higher than 500 and 200 Gy for protons of 1 and 3 MeV, respectively. The detectors demonstrated linear responses, very low sensitivity dispersion per set of samples, and excellent stability after irradiation. This shows that, with an appropriate readout system, the RADFET can become an excellent system for high-dose proton beams.
Application of a sensitive LSC measurement procedure to the determination of 3H in drinking water and rainwater in the city of Seville
(Elsevier, 2026-06) García León, José Luis; García León, Manuel; Manjón Collado, Guillermo; Física Aplicada I; Física Atómica, Molecular y Nuclear; Física Aplicada II; Gobierno de España; RNM138: Física Nuclear Aplicada
A sensitive 3H analytical procedure based on electrolytic enrichment and the use of the liquid scintillation spectrometer Quantulus GCT 6220 has been recently implemented in the University of Seville to routinely determine this radionuclide in drinking water and rainwater. Using this optimized technique, it has been possible to continue the monitoring work despite the decrease in the global levels of available 3H. In this study, we present the results obtained in drinking water from 2006 to 2025. In addition, results are given for rainwater samples collected between 2023 and 2025. Seasonal effects were analyzed for both sets of samples and the correlation of the activity concentration in rainwater with rainfall was examined. The possibility of performing 3H determinations in acidified water samples was explored to enlarge the time series.

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