jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Rafael G. Suárez | I. Betancourt | Jesús Arenas | M. Camacho | Israel Núñez-Tapia | J. M. Zamora
Source: Materials (article, 2026-03-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Correlation Between Microstructural Evolution and Magnetocaloric Response in Suction-Cast MnCoGeB0.02 Alloy Magnetic and structural transitions can interact significantly, leading to an enhanced magnetocaloric effect (MCE), also known as the giant or colossal effect. In this study, we investigate how subtle microstructural changes impact the magnetocaloric behavior of a MnCoGeB<sub>0.02</sub> alloy fabricated via suction casting. We obtained conical samples and analyzed them to understand their structure and magnetic properties. X-ray diffraction patterns revealed a coexistence of a metastable high-temperature hexagonal phase and a stable low-temperature orthorhombic phase in different regions of each cone. The presence and proportion of these phases determine the degree of magneto-structural coupling, which in turn influences the MCE. The magnetic entropy change (<b>|</b>Δ<i>S</i><sub>Peak</sub><b>|</b>) varied notably among the samples, ranging from 12.3 to 6 Jkg<sup>-1</sup>K<sup>-1</sup> under a magnetic field change of Δµ<sub>0</sub><i>H</i> = 5.0 T. These findings demonstrate that even minor microstructural changes caused by differences in solidification during suction casting can lead to noticeable variations in magnetocaloric performance. Understanding and controlling these microstructural details is vital for optimizing the functional behavior of MnCoGe-based materials. Magnetic refrigeration ; Alloy ; Orthorhombic crystal system ; Metastability ; Microstructure ; Magnetic shape-memory alloy ; Phase (matter) ; Conical surface ; Martensite Magnetic and transport properties of perovskites and related materials ; Shape Memory Alloy Transformations ; High Entropy Alloys Studies
Authors: Neil Moffat | Jose Alfonso Soto Oton | Gemma Rius | Enric Cabruja | Giulio Pellegrini
Source: Scientific Reports (article, 2026-01-11)
Field: Materials Science — Materials Chemistry

A graphene-on-silicon photodetector for low penetrating radiation We introduce an innovative graphene-on-silicon photodiode designed for low penetrating radiation. Its standout feature lies in its remarkably-thin dead layer in the entrance window, setting it apart from existing photodetectors. Conventional photodetectors suffer from sensitivity limitations in the low wavelength or energy, respectively, for light or particles, due to their shallow penetration depth. Most conventional photodiodes employ a junction implant which suffers from recombination of low-penetrating photons/particles within the dead layer. Instead, we utilise the nearly transparent properties of single-layer graphene to create a depletion layer that minimises the dead layer. We combine a single junction ring (highly doped [Formula: see text] bias ring) with single-layer graphene. The graphene acts as a field plate, extended over the junction ring and covering the entire entrance window (5×5 [Formula: see text] active area), while being electrically isolated by an ultrathin, high K dielectric layer. In operation, the photodiode undergoes depletion upon applying a reverse bias as expected, which primarily occurs within the region beneath the field plate. We conducted Transient Current Technique measurements as the best method to assess the charge collection uniformity of the device. Remarkably, the results reveal a consistent total 100% uniformity across the entire detector area. Nevertheless, while the collection time is position-dependent, increasing as the laser incidence point moves farther away from the bias ring, responsivity measurements show excellent response in both the deep ultra violet and vacuum ultra violet regions with ≥ 100% external quantum efficiency at wavelengths below 150 nm. Photodetector ; Responsivity ; Photodiode ; Quantum efficiency ; Depletion region ; Detector ; Wavelength ; Penetration depth ; Active layer Graphene research and applications ; Plasmonic and Surface Plasmon Research ; Thin-Film Transistor Technologies
Authors: Wei Ren | Shiyu Guo | Dean Long | N. Friedman | Jingyuan Xian | David Li | Jack Tavakley | Jeongsoo Park | Kenji Watanabe | Takashi Taniguchi | Ke Wang
Source: ArXiv.org (article, 2026-02-11)
Field: Materials Science — Materials Chemistry

Ferroelectric Quantum Point Contact in Twisted Transition Metal Dichalcogenides In twisted transition metal dichalcogenides (tTMDs), atomic reconstruction gives rise to moiré domains with alternating ferroelectric polarization, whose domain size and overall electric dipole moment are tunable by an out-of-plane electric field. Previous transport measurements in Hall bar devices have successfully demonstrated the overall ferroelectric behavior of tTMDs from a collective ensemble of ferroelectric moiré domains. To locally probe a single ferroelectric moiré domain, we fabricate and study mesoscopic quantum transport via a gate-defined twisted molybdenum disulfide (tMoS2) quantum point contact (QPC). The local property of a single moiré domain is invulnerable to long-range disorder and twist-angle inhomogeneity, resulting in an unusually long conductance plateau with large electrical hysteresis. The comparison between local and global measurements confirms that antiferroelectricity can emerge from alternating polarization of individual ferroelectric domains. Using a QPC as a single charge sensor, we characterize the nature and time scale of different domain evolution mechanisms with single atomic dipole resolution. Our findings shed new light on the microscopic ferroelectric behavior and dynamics within a single tTMD moiré domain, paving the way toward more advanced ferroelectric quantum devices with tunable local Hamiltonian, such as ferroelectric tTMD quantum dots (QDs). Ferroelectricity ; Dipole ; Quantum point contact ; Mesoscopic physics ; Polarization (electrochemistry) ; Quantum ; Electric field 2D Materials and Applications ; Topological Materials and Phenomena ; Graphene research and applications
Authors: Daoud Kouzrit | Habib Khouni | Nacerdine Bourouba | Nacerdine Bouzit | Abdelhalim Brahimi | Martinez J. Juan Pablo
Source: Annales de Chimie Science des Matériaux (article, 2026-02-28)
Field: Materials Science — Materials Chemistry

Oxide Effect on the Dielectric Behavior of a Ternary Titanate-Based Composite: Exploration on Broadband Dielectric Permittivity This article examines the dispersion phenomenon and the influence of silicon dioxide (SiO2) on the complex permittivity of binary composites made of epoxy resin (RE) and barium titanate (BaTiO).Using Time-Domain Spectroscopy (TDS), the samples were characterized over a frequency range from DC to 30 GHz.The volume fractiondependent relative permittivity of these composites was modeled using the modified Lichtenecker mixing law (MLL).Numerical optimization was employed to refine the model parameters, offering predictive insights into dielectric permittivity and shape factor coefficients for ternary composites.Comparative analysis confirms the model's suitability for binary and ternary composites, with an efficiency estimated at an average error of less than 2%.A Lorentzian resonance model is proposed to characterize the frequency-dependent behavior of the complex permittivity.The frequency dispersion profile of this ternary composite permittivity, exhibiting both relaxation and resonance spectra, shows a clear evolution with increasing BaTiO content.Our empirical model provides a robust description of the resonance-type complex permittivity for BaTiO and silica composites.The inclusion of SiO2 in the binary composite produced remarkable effects on the composite permittivity and loss tangent (tan ) values, as these dropped drastically by 60%.These materials are promising for the miniaturization of electronic components in microelectronics and telecommunications applications. Dielectric ; Permittivity ; Ternary operation ; Oxide ; Dielectric permittivity ; Broadband Ferroelectric and Piezoelectric Materials ; Dielectric properties of ceramics ; Dielectric materials and actuators
Authors: A. S. Kuznetsov | Valentino Pistore | Lutz Schrottke | K. Biermann | Xiang Lü
Source: arXiv (Cornell University) (article, 2026-03-24)
Field: Chemistry — Spectroscopy

GHz control of THz QCL band structure and gain by standing acoustic strain Active frequency comb generation and waveform control are central challenges in the terahertz (THz) domain. In THz quantum cascade lasers (QCLs), these functions have typically been achieved through active bias modulation, which alters the operating point of the device and imposes severe limitations on its flexibility. To address these challenges, we propose an approach based on the direct modulation of the QCL bandstructure using GHz-frequency standing bulk acoustic waves (BAWs), promising direct and localized control of the optical gain and chromatic dispersion. To this end, we fabricated a bulk acoustic transducer on top of a THz QCL in order to excite GHz standing BAWs within its active region. We demonstrate that radio-frequency driving of the transducer leads to the tunable generation of standing BAWs in 5-12 GHz frequency range with wavelengths commensurate to the QCL period length. The effect of the BAW on the QCL bandstructure is revealed by measuring photoluminescence (PL) of the active region, where the BAW strain leads to a considerable modulation of the PL energy up to a few meV around its non-modulated value. We also develop a model and perform bandstructure simulations to predict the effect of the BAW on the QCL subband structure and gain. These results mark the first demonstration of dynamic bandstructure modulation in a THz QCL using GHz acoustic strain, introducing a fundamentally new paradigm that establishes a powerful synergy between QCLs and BAWs towards coherent control and frequency comb engineering in the THz domain. Terahertz radiation ; Modulation (music) ; Frequency modulation ; Transducer ; Chirp ; Wavelength ; Gallium arsenide ; Waveform Spectroscopy and Laser Applications ; Advanced Fiber Laser Technologies ; Cold Atom Physics and Bose-Einstein Condensates
Authors: W. Akbar | Andrzej Biborski | Louk Rademaker | M. Zegrodnik
Source: Scientific Reports (article, 2026-03-30)
Field: Materials Science — Materials Chemistry

Unconventional superconductivity in the presence of long-range interactions in transition metal dichalcogenide moiré heterobilayers Transition-metal dichalcogenide (TMD) moiré systems have recently garnered much attention as platforms for studying electron-correlation-induced effects as well as unconventional superconductivity (SC). Here we analyze the principal features of the unconventional superconducting state in a TMD moiré flat band in the strongly correlated regime and in the presence of significant intersite Coulomb repulsion as well as long-range hopping and exchange interaction terms. In our study, we use the extended versions of both the t-J-U and t-J models and apply the Gutzwiller approximation method to incorporate the effects of electron-electron interactions. We show that in the strongly correlated regime and close to half-filling, the superconducting state is strongly immune to the negative effect of the V-term on the pairing, and shows a two-dome behavior with a Mott insulating state residing at half-filling. We explain this result as originating from relatively strong renormalization of the intersite interaction terms, caused by the significant value of the onsite Coulomb repulsion. As we show, this mechanism allows the superconductivity to persist even for relatively large values of V, which are characteristic for the WS[Formula: see text]/WSe[Formula: see text] heterobilayer. Such a result emphasizes the potential of the WS[Formula: see text]/WSe[Formula: see text] heterobilayer as another candidate for unconventional SC in the family of moiré flat band systems. Superconductivity ; Transition metal ; Metal ; Transition temperature ; Superconducting transition temperature ; Phase transition 2D Materials and Applications ; Iron-based superconductors research ; Graphene research and applications
Authors: Siyang Cai | Cangyuan Li | Yinhe Han | Ying Wang
Source: ArXiv.org (article, 2026-03-10)
Field: Materials Science — Materials Chemistry

Wrong Code, Right Structure: Learning Netlist Representations from Imperfect LLM-Generated RTL Learning effective netlist representations is fundamentally constrained by the scarcity of labeled datasets, as real designs are protected by Intellectual Property (IP) and costly to annotate. Existing work therefore focuses on small-scale circuits with clean labels, limiting scalability to realistic designs. Meanwhile, Large Language Models (LLMs) can generate Register-Transfer-Level (RTL) at scale, but their functional incorrectness has hindered their use in circuit analysis. In this work, we make a key observation: even when LLM-Generated RTL is functionally imperfect, the synthesized netlists still preserve structural patterns that are strongly indicative of the intended functionality. Building on this insight, we propose a cost-effective data augmentation and training framework that systematically exploits imperfect LLM-Generated RTL as training data for netlist representation learning, forming an end-to-end pipeline from automated code generation to downstream tasks. We conduct evaluations on circuit functional understanding tasks, including sub-circuit boundary identification and component classification, across benchmarks of increasing scales, extending the task scope from operator-level to IP-level. The evaluations demonstrate that models trained on our noisy synthetic corpus generalize well to real-world netlists, matching or even surpassing methods trained on scarce high-quality data and effectively breaking the data bottleneck in circuit representation learning. Netlist ; Representation (politics) ; Bottleneck ; Scalability ; Pipeline (software) ; Task (project management) ; Identification (biology) ; Synthetic data ; Imperfect ; Matching (statistics) Machine Learning in Materials Science ; Physical Unclonable Functions (PUFs) and Hardware Security ; Advanced Graph Neural Networks
Authors: Seokjun Kim | Haneul Ryu | Minseok Kim
Source: ArXiv.org (article, 2026-01-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Non-Local Metasurface-aided Leaky-Wave Antennas This work presents a non-local terahertz metasurface integrated into a leaky-wave antenna for robust, wide-angle beam steering. The metasurface encodes a holographic pattern by explicitly inducing tangential and normal susceptibilities, along with magnetoelectric coupling. This design maintains stable radiation performance even when the longitudinal wavenumber of the incident guided mode - and thus its effective impinging angle - varies as a function of frequency. In particular, we show that there exists a limit to achieving exact angular insensitivity and propose an optimization-based framework to obtain the required susceptibilities that closely approximate near angle-insensitive performance for stable beam-steering performance. Additionally, an iterative synthesis approach is introduced that maps abstract susceptibilities to physically realizable structures. Full-wave simulations demonstrate a beam-scanning range of nearly 50 degrees over the 2.0-2.7 THz band - a more than threefold improvement over conventional local-metasurface designs. Terahertz radiation ; Limit (mathematics) ; Antenna (radio) ; Wavenumber ; Mode (computer interface) ; Beam (structure) ; Function (biology) ; Point (geometry) ; Range (aeronautics) Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Antenna Design and Analysis
Authors: Josie Franks | Eric Masson
Source: Chemical Science (article, 2026-01-01)
Field: Chemistry — Organic Chemistry

Accurate prediction of cucurbituril binding affinities from guest molecular formulae The binding affinities of 24 ammonium salts were determined by isothermal titration calorimetry (ITC). The affinities were predicted with three empirical models that do not invoke the macrocycle explicitly. Once head groups common to all guests are removed, and the remaining fragments are transferred from aqueous solution to a virtual gas phase, the free energy of transfer from the gas phase to the CB[7] cavity is correlated with (a) the dispersive component of their interaction with a non-polar, non-polarizable hard sphere fluid, (b) their free energy of solvation in tetramethylglycoluril, that mimics the main building block of CB[7], and (c) a sum of individual guest atom free energy contributions <i>via</i> multiple linear regression. The latter method, which simply correlates binding affinities with the guest molecular formulae, is the most precise and accurate one, except for tight-fitting guests, with mean absolute errors as low as 0.16 kcal mol<sup>-1</sup>, thereby rivaling experimental error (0.06 kcal mol<sup>-1</sup> on average). Accuracy exceeds density functional theory calculations that treat the host explicitly. Affinities ; Isothermal titration calorimetry ; Cucurbituril ; Binding affinities ; Calorimetry ; Titration Supramolecular Chemistry and Complexes ; Crystallography and molecular interactions ; Mass Spectrometry Techniques and Applications
Authors: Bakr Sadiq Mohammed | Nagham Shakir Turkey
Source: Analytical Methods in Environmental Chemistry Journal (article, 2026-03-01)
Field: Chemistry — Analytical Chemistry

Continuous flow injection analysis based on NAG-4SX3-3D analyzer for the determination of copper using solid particulate precipitate with calcium hexacyanoferrate and validation by UV-Spectrophotometry and F-AAS This study introduces a novel flow injection analysis (FIA) method for rapid, accurate detection of Cu(II) ions using calcium hexacyanoferrate and potassium chloride. Using the NAG-4SX3-3D Analyzer, the sensor's energy response was evaluated, yielding consistent and reliable results. The study established a linear range for copper(II) detection from 0.005 mM to 5.0 mM (0.318-317.75 mg L-1), with a low relative standard deviation (RSD%) of less than 0.23% at 1.5 mM and 4.5 mM across nine replicates. The limit of detection (LOD) was determined to be 12.901 ng per sample (12.901 µgL-1 based on a 1.0 mL injection) through progressive dilution analysis, using the minimum concentration on the calibration curve. Detector FIA was photometric/turbidimetric at 620 nm (bandpass ~10 nm). The linear dynamic range (LDR) showed a strong correlation (r = 0.9853) and a high coefficient of determination (R² = 99.07). A comparison with the traditional UV-spectrophotometric method at λmax = 296nm underscored the technique's heightened sensitivity, efficient use of chemicals, and superior results. Additionally, the accuracy of the copper concentration results in the samples was validated using UV spectrophotometry and flame atomic absorption spectroscopy (F-AAS) after dilution, with a calibration range of 0.05–5.0 mg L⁻¹. Analytical Chemistry (journal) ; Detection limit ; Copper ; Calibration ; Flow injection analysis ; Dilution ; Calibration curve ; Atomic absorption spectroscopy ; Spectrum analyzer Analytical chemistry methods development ; Water Quality Monitoring and Analysis ; Analytical Chemistry and Sensors
Authors: Husna Mat Salleh | Nur Hidayah Ahmad Zaidi | Nur Maizatulshima Adzali | Siti Hasanah Osman
Source: International Journal of Innovation and Industrial Revolution (article, 2026-03-01)
Field: Materials Science — Biomaterials

MICROSTRUCTURAL EVOLUTION AND THERMAL STABILITY ANALYSIS OF AZ91 MAGNESIUM NANOCOMPOSITES UNDER CONTROLLED THERMAL EXPOSURE This study investigates the microstructural evolution and thermal stability of AZ91 magnesium nanocomposites under controlled thermal exposure conditions. The purpose of this work is to evaluate the effectiveness of nanoparticle reinforcement in enhancing microstructural stability, phase retention, and resistance to thermal degradation in AZ91 magnesium alloy for elevated-temperature applications.AZ91-based nanocomposites and unreinforced AZ91 alloy were subjected to controlled thermal exposure at elevated temperatures for different durations. Microstructural characterisation was carried out using optical microscopy, scanning electron microscopy, and transmission electron microscopy to analyse grain evolution, phase morphology, and interfacial stability, with particular emphasis on the thermally sensitive β-Mg₁₇Al₁₂ phase. The results demonstrate that the unreinforced AZ91 alloy undergoes significant grain growth and β-phase coarsening during thermal exposure. In contrast, the AZ91 nanocomposites exhibit refined microstructures, suppressed grain growth, and improved stability of the β-Mg₁₇Al₁₂ phase. These improvements are attributed to the grain boundary pinning effect and diffusion-restricting behaviour of nanoparticles, which delay microstructural degradation under thermal loading. In conclusion, nanoparticle reinforcement significantly enhances the thermal stability of AZ91 magnesium alloy by stabilising microstructural features and retarding phase degradation during prolonged thermal exposure. The findings confirm that AZ91 magnesium nanocomposites are promising candidates for applications requiring reliable performance in thermally demanding environments. Nanocomposite ; Microstructure ; Thermal stability ; Magnesium alloy ; Magnesium ; Grain boundary ; Alloy ; Grain size Magnesium Alloys: Properties and Applications ; Aluminum Alloys Composites Properties ; Aluminum Alloy Microstructure Properties
Authors: Mehmet Kepenekci | Kun-Chieh Chien | Natalia Andrea Rueda Guerrero | Kwon Sang Lee | Chih-Hao Chang
Source: Nanoscale (article, 2026-01-01)
Field: Materials Science — Materials Chemistry

From resilience to scratch resistance: engineering the deformation mechanisms of nanostructured surfaces Nanostructured materials and engineered surfaces have attracted significant attention for their unique physical properties in multiple domains. The structural geometry and material composition have a profound influence on the mechanical behavior of these structures but have yet to be systematically examined. This work investigates the effect of the pillar aspect ratio and intrinsic material properties on the deformation mechanisms of sapphire and silicon nanopillar arrays. Using nanoindentation, the modulus, hardness, and scratch resistance of silicon and sapphire nanopillar arrays with various aspect ratios are characterized. The results indicate that low aspect ratio nanopillar arrays have high hardness and stiffness but are brittle and fail through material fracture. On the other hand, high aspect ratio nanopillars are more resilient and exhibit recoverable deformation through structure buckling and bending. The sapphire nanopillar arrays are more mechanically robust compared to silicon and have modulus and hardness comparable to bulk glass and other scratch-resistant metals. The findings guide the development of mechanically robust nanostructured materials with optimized surface properties and can find applications in nanophotonics, multifunctional surfaces, and nanoscale devices. Nanopillar ; Brittleness ; Deformation (meteorology) ; Silicon ; Sapphire ; Stiffness ; Aspect ratio (aeronautics) ; Nanostructure ; Nanoscopic scale Microstructure and mechanical properties ; Metal and Thin Film Mechanics ; Force Microscopy Techniques and Applications