jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Federica Ursi | Simone Virga | Candida Pipitone | Alessandra Sanson | Alessandro Longo | Francesco Giannici | Antonino Martorana
Source: Journal of Applied Crystallography (article, 2023-03-07)
Field: Materials Science — Materials Chemistry

Modelling the structural disorder in trigonal-prismatic coordinated transition metal dichalcogenides Trigonal-prismatic coordinated transition metal dichalcogenides (TMDCs) are formed from stacked (chalcogen)-(transition metal)-(chalcogen) triple layers, where the chemical bond is covalent within the triple layers and van der Waals (vdW) forces are effective between the layers. Bonding is at the origin of the great interest in these compounds, which are used as 2D materials in applications such as catalysis, electronics, photoelectronics, sensors, batteries and thermoelectricity. This paper addresses the issue of modelling the structural disorder in multilayer TMDCs. The structural model takes into account stacking faults, correlated displacement of atoms and average crystallite size/shape, and is assessed by simulation of the X-ray diffraction pattern and fitting to the experimental data relative to a powdered sample of MoS<sub>2</sub> exfoliated and restacked via lithiation. From fitting, an average crystallite size of about 50 Å, nearly spherical crystallites and a definite probability of deviation from the fully eclipsed atomic arrangement present in the ordered structure are determined. The increased interlayer distance and correlated intralayer and interlayer atomic displacement are attributed to the presence of lithium intercalated in the vdW gap between triple layers (Li/Mo molar ratio of about 0.06). The model holds for the whole class of trigonal-prismatic coordinated TMDCs, and is suitably flexible to take into account different preparation routes. Trigonal prismatic molecular geometry ; Trigonal crystal system ; Transition metal ; Crystallography ; Materials science ; Chemistry ; Chemical physics ; Crystal structure ; Octahedron ; Catalysis 2D Materials and Applications ; Nanoplatforms for cancer theranostics ; Graphene research and applications
Authors: Luigi Crisci | Federico Coppola | Alessio Petrone | Nadia Rega
Source: Journal of Computational Chemistry (article, 2023-09-14)
Field: Chemistry — Physical and Theoretical Chemistry

Tuning ultrafast time‐evolution of photo‐induced charge‐transfer states: A real‐time electronic dynamics study in substituted indenotetracene derivatives Photo-induced charge transfer (CT) states are pivotal in many technological and biological processes. A deeper knowledge of such states is mandatory for modeling the charge migration dynamics. Real-time time-dependent density functional theory (RT-TD-DFT) electronic dynamics simulations are employed to explicitly observe the electronic density time-evolution upon photo-excitation. Asymmetrically substituted indenotetracene molecules, given their potential application as n-type semiconductors in organic photovoltaic materials, are here investigated. Effects of substituents with different electron-donating characters are analyzed in terms of the overall electronic energy spacing and resulting ultrafast CT dynamics through linear response (LR-)TD-DFT and RT-TD-DFT based approaches. The combination of the computational techniques here employed provided direct access to the electronic density reorganization in time and to its spatial and rational representation in terms of molecular orbital occupation time evolution. Such results can be exploited to design peculiar directional charge dynamics, crucial when photoactive materials are used for light-harvesting applications. Ultrashort pulse ; Charge (physics) ; Time evolution ; Chemical physics ; Dynamics (music) ; Computational chemistry ; Materials science ; Statistical physics ; Physics ; Atomic physics ; Chemistry ; Quantum mechanics Photochemistry and Electron Transfer Studies ; Photoreceptor and optogenetics research ; Spectroscopy and Quantum Chemical Studies
Authors: Yajun Zhang | Jingtong Zhang | Jiahang Li | P. S. Sahoo | Xu He | Jie Wang | Philippe Ghosez
Source: Physical review. B./Physical review. B (article, 2023-10-12)
Field: Materials Science — Materials Chemistry

Displacive phase transitions in infinite-layer nickelates from first- and second-principles calculations Antiferrodistortive (AFD) motions in ${ABX}_{3}$ perovskites play an important role in determining, tuning, and creating functionalities. Here, through first-principles calculations, we predict that the AFD motions in $R{\mathrm{NiO}}_{2}$ (where $R$ denotes rare-earth ion), which recently gained significant interest as superconductor systems, show very similar behaviors with perovskites in various aspects, indicating an intrinsic property. The origin of AFD motions is rationalized by chemical bond valence theory, and we reveal that the undercoordination of the $R$ cation is the driving force for the appearance of rotation, analogous to perovskites. Going further, the temperature dependence of local deformations is addressed by developing a second-principles model, and we suggest that the structural phase transitions should be classified as displacive. Eventually, a direct rotation-electron-spin connection is established, which opens a pathway to purposefully tune the Fermi surface, magnetic coupling strength, and magnetic dimensionality. Given that superconducting properties are associated with electronic and magnetic properties, our results provide the possibility and feasibility of the practical control of behaviors in nickelate superconductors through rotation engineering. Condensed matter physics ; Superconductivity ; Valence (chemistry) ; Coupling (piping) ; Phase (matter) ; Curse of dimensionality ; Valence bond theory ; Rotation (mathematics) ; Electronic structure ; Physics ; Materials science ; Electron ; Quantum mechanics ; Atomic orbital Ferroelectric and Piezoelectric Materials ; Magnetic and transport properties of perovskites and related materials ; Multiferroics and related materials
Authors: Ronghuan Sun | Yong Liu | Ying Chen | Qi Jiang | Pingan Chen | Shuai Qin | Ziyu Luo | Xin Yang | Ying Jiang | Yuanyuan Hu | Shula Chen | Anlian Pan
Source: Science China Materials (article, 2023-04-17)
Field: Materials Science — Materials Chemistry

Efficient enhancement of photoluminescence and second-harmonic generation of few-layer InSe coupled with surface-plasmonic Ag prism array Materials science ; Optoelectronics ; Exciton ; Polarization (electrochemistry) ; Photoluminescence ; Ray ; Optics ; Physics ; Condensed matter physics ; Chemistry 2D Materials and Applications ; Perovskite Materials and Applications ; Semiconductor Quantum Structures and Devices
Authors: Enidale Yazie Muluneh | Menbere Leul Mekonnen | Siraye Esubalew Debebe
Source: ChemistrySelect (article, 2023-08-09)
Field: Chemistry — Electrochemistry

Determination of Lead(II) and Cadmium(II) in Selected Commercially Available Water‐Based Paints of Ethiopia by Anodic Stripping Voltammetry Using a Bismuth‐Modified Glassy Carbon Electrode Abstract Since the introduction of bismuth‐modified electrodes in Anodic Stripping Voltammetry, it has been used to determine heavy metals in various matrices. However, most reports focused on water samples due to fewer sample treatment requirements. In this study, Square Wave Anodic Stripping Voltammetry technique with a bismuth‐modified glassy carbon electrode is reported for the simultaneous determination of lead and cadmium content in paints. Analysis of paint samples collected from three industries in Ethiopia showed excellent percent recovery values ranging from 97.99–102.07 %. The Pb and Cd contents in these products have not been reported yet. The limits of detection were 0.06 μmol/L for Pb(II) and 0.13 μmol/L for Cd(II). The concentration of Cd(II) is not in the detectable range (ND) in all paint samples. The concentration Pb(II) in paint samples of DH‐Geda (Green 3.41±0.62 ppm, Red 14.05±0.91 ppm, violate 11.23±1.08 ppm and White 12.04±0.57 ppm), Nefas silk (Green 2.95±0.29 ppm, Red 3.16±0.36 ppm, violate 7.42±0.83 ppm, and White 6.93±0.79 ppm) and Tsehay (Green 4.40±0.67 ppm, Red ND, Violate ND, and White ND). These results are cross‐checked with AAS and the result is almost the same. This method is not significantly influenced by the paint matrix and can be used as an alternative analytical method for the determination of heavy metals in the paint matrix. The amount of Pb(II) and Cd(II) in the given paints are below the permissible levels based on the regulation of Ethiopia (90 ppm for Pb). Therefore, they are safe to use in the country. Anodic stripping voltammetry ; Bismuth ; Cadmium ; Voltammetry ; Stripping (fiber) ; Detection limit ; Nuclear chemistry ; Matrix (chemical analysis) ; Analytical Chemistry (journal) ; Glassy carbon ; Carbon fibers ; Chemistry ; Materials science ; Electrode ; Cyclic voltammetry ; Electrochemistry ; Metallurgy ; Environmental chemistry ; Chromatography ; Composite material Electrochemical Analysis and Applications ; Analytical Chemistry and Sensors ; Electrochemical sensors and biosensors
Authors: Kjetil Baglo | Marco Sauermoser | Markus Joakim Lid | Thomas Paschke | Abdulla Bin Afif | Markus Lunzer | Andreas L. Flåten | Martin Steinert | Robert Bock | Jan Torgersen
Source: Advanced Materials Technologies (article, 2023-04-04)
Field: Materials Science — Polymers and Plastics

Overcoming the Transport Limitations of Photopolymer‐Derived Architected Carbon Abstract Photopolymer derived carbon grows in popularity, yet the range in available feature sizes is limited. Herein, the focus is on expanding the field to low surface to volume ratio (SVR) structures. A high temperature acrylic photopolymerizable precursor with FTIR and DSC is described and a thermal inert‐gas treatment is developed for producing architected carbon in the mm scale with SVR of 1.38×10 −3 µm −1 . Based on thermogravimetric analysis and mass spectrometry, two thermal regimes with activation energies of ≈79 and 169 kJ mol −1 are distinguished, which is reasoned with mechanisms during the polymer's morphologic conversion between 300 and 500 °C. The temperature range of the major dimensional shrinkage (300–440 °C, 50%) does not match the range of the largest alteration in elemental composition (440–600 °C, O/C 0.25–0.087%). The insights lead to an optimized thermal treatment with an initial ramp (2 °C min −1 to 350 °C), isothermal hold (14 h), post hold ramp (0.5 °C min −1 to 440 °C) and final ramp (10 °C min −1 to 1000 °C). The resulting carbon structures are dimensionally stable, non‐porous at the µm scale, and comprise an unprecedented variation in feature sizes (from mm to µm scale). The findings shall advance architected carbon to industrially relevant scales. Thermogravimetric analysis ; Carbon fibers ; Isothermal process ; Photopolymer ; Materials science ; Shrinkage ; Polymer ; Thermal ; Porosity ; Polymerization ; Atmospheric temperature range ; Fourier transform infrared spectroscopy ; Range (aeronautics) ; Volume (thermodynamics) ; Chemical engineering ; Analytical Chemistry (journal) ; Composite material ; Chemistry ; Thermodynamics ; Organic chemistry Polymer Nanocomposites and Properties ; Photopolymerization techniques and applications ; Additive Manufacturing and 3D Printing Technologies
Authors: Igor A. Lavrinchenko | Timofey D. Moseev | Yuri A. Seleznev | Михаил В. Вараксин | Anton N. Tsmokaluk | Valery N. Charushin | Олег Н. Чупахин
Source: Asian Journal of Organic Chemistry (article, 2023-02-21)
Field: Chemistry — Organic Chemistry

Blue‐Emitting 2‐Fluoroaryl‐1,2,3‐Triazole Fluorophores: Synthesis, Theoretical Calculations, and Optical Properties Abstract A convenient multistep synthetic methodology to afford prospective push‐pull fluorophores based on the N(2)‐fluoroaryl‐1,2,3‐triazole scaffold as valuable functional blocks in the design of blue‐emitting organic materials is reported. The strategy includes five synthetic steps with yields of 60–99% at each stage. The obtained photoactive molecules, 2‐fluoroaryl‐5‐aryl‐4‐methyl‐1,2,3‐triazoles, were found to possess a blue‐violet emission in the range of λ=330–440 nm and the absolute quantum yield of &gt;99% in solvents of different polarities. The electron transfer mechanistic features in the excited states for the developed N(2)‐fluoroaryl‐1,2,3‐triazoles compared to the 1,2,3‐triazoles‐1‐oxide analogues were also studied by using DFT and CIS calculations. Chemistry ; Quantum yield ; Yield (engineering) ; Triazole ; Molecule ; Excited state ; Photochemistry ; Combinatorial chemistry ; Aryl ; Fluorescence ; Computational chemistry ; Organic chemistry Click Chemistry and Applications ; Fluorine in Organic Chemistry ; Synthesis and Biological Evaluation
Authors: Andrea C. Ferrari | Alexander A. Balandin
Source: Applied Physics Letters (article, 2023-02-13)
Field: Materials Science — Materials Chemistry

Phononics of graphene, layered materials, and heterostructures First Page Graphene ; Heterojunction ; Materials science ; Nanotechnology ; Condensed matter physics ; Optoelectronics ; Physics Thermal properties of materials ; Graphene research and applications ; Thermal Radiation and Cooling Technologies
Authors: Thinh N. Tran | Angus Gale | Benjamin Whitefield | Vladimir Dyakonov | Milos Toth | Igor Aharonovich | Mehran Kianinia
Source: Applied Physics Letters (article, 2023-07-17)
Field: Materials Science — Materials Chemistry

Coupling spin defects in hexagonal boron nitride to a microwave cavity Optically addressable spin defects in hexagonal boron nitride (hBN) have become a promising platform for quantum sensing. While sensitivity of these defects is limited by their interactions with the spin environment in hBN, inefficient microwave delivery can further reduce their sensitivity. Here, we design and fabricate a microwave double arc resonator for efficient transferring of the microwave field at 3.8 GHz. The spin transitions in the ground state of VB− are coupled to the frequency of the microwave cavity, which result in enhanced optically detected magnetic resonance (ODMR) contrast. In addition, the linewidth of the ODMR signal further reduces, achieving a magnetic field sensitivity as low as 42.4 μT/√Hz. Our robust and scalable device engineering is promising for future employment of spin defects in hBN for quantum sensing. Laser linewidth ; Microwave ; Materials science ; Spin (aerodynamics) ; Optoelectronics ; Boron nitride ; Coupling (piping) ; Resonator ; Sensitivity (control systems) ; Microwave cavity ; Magnetic field ; Condensed matter physics ; Nanotechnology ; Optics ; Physics ; Electronic engineering ; Laser Diamond and Carbon-based Materials Research ; Quantum optics and atomic interactions ; Magneto-Optical Properties and Applications
Authors: P. Crozet | J. Morin | Amanda Ross | S. Bellotti | J.‐F. Donati | P. Fouqué | C. Moutou | P. Petit | A. Carmona | Á. Kóspál | A. G. Adam | D. W. Tokaryk
Source: Astronomy and Astrophysics (article, 2023-10-06)
Field: Chemistry — Spectroscopy

Correlations between laboratory line lists for FeH, CrH, and NiH and M-star spectra collected with ESPaDOnS and SPIRou Context. Molecular bands of metal oxides and hydrides dominate the optical and near-infrared spectra of M dwarfs. High-resolution spectra of these bands have immense potential for determining many properties of these stars, such as effective temperature, surface gravity, elemental abundances, radial velocity, or surface magnetic fields. Techniques are being developed to do this but remain limited by the current availability and accuracy of molecular data and spectral line lists. Aims. This paper reports metal monohydride line lists selected from near-infrared and visible laboratory data to show that specific bands in several electronic transitions can be used to identify CrH, NiH, and FeH in M stars and to determine radial velocities from Doppler shifts. The possibility of measuring magnetic fields is also investigated for FeH and CrH. Methods. We used systematic cross-correlation analysis between unpolarised spectra from a selection of M stars and state-specific laboratory line lists. These lists were generated from a combination of existing data and new laboratory laser-excitation spectra recorded at Doppler-limited resolution, in zero-field conditions or in magnetic fields up to 0.6 tesla. Results. We show that transitions at visible wavelengths in FeH and NiH, usually neglected in the analysis of the spectra of M-type stars, do in fact contribute to the spectra, and we demonstrate the influence of magnetic sensitivity on selected transitions in CrH and FeH. Conclusions. Although the new line lists focus on transitions recorded at temperatures significantly lower than those of stellar objects, they remain pertinent because they cover some band-head regions of high spectral density. FeH bands can provide a useful supplement to atomic lines for the analysis of high-resolution optical and near-infrared spectra of M dwarfs. We demonstrate the influence of a magnetic field on CrH signatures around 862 nm. Stars ; Physics ; Spectral line ; Astrophysics ; Context (archaeology) ; Line (geometry) ; Radial velocity ; Surface gravity ; Spectroscopy ; Spectral resolution ; Stellar classification ; Magnetic field ; Doppler effect ; Astronomy Mass Spectrometry Techniques and Applications
Authors: Daisuke Takimoto | Keisuke Suzuki | Sho Hideshima | Wataru Sugimoto
Source: Electrochemistry (article, 2023-06-08)
Field: Materials Science — Polymers and Plastics

Origin of the Adsorption-Controlled Redox Behavior of Quinone-Based Molecules: Importance of the Micropore Width Redox-active organic materials have emerged as promising alternatives to inorganic electrode materials in electrochemical devices owing to advantages such as low cost and flexible design. However, the kinetics of their electrochemical reactions are typically slow due to the slow diffusion of organic materials dissolved in the electrolyte. Generally, peak separation of the redox reaction is observed (mass-transfer-controlled system), while no peak separation is obtained when the active molecules, such as high surface carbon material, are adsorbed onto the electrode material (adsorption-controlled system). Aromatic compounds confined in activated carbon (AC) micropores exhibit an adsorption-controlled reaction, improving the reaction kinetics. To elucidate this behavior, a well-defined and accurate understanding of the pore geometry is required. Although various synthetic techniques have been used to tune the micropore size, these afford different surface properties. This study reports an approach to achieve an adsorption-controlled redox reaction of quinone-based molecules and a tool to analyze their reaction environment. AC micropores sized <1 nm were filled with n-nonane without any change occurring in the AC surface properties. It was thus concluded that AC micropores in the sub-nanometer scale are necessary for an adsorption-controlled redox reaction to occur. This study reveals new insights on the micropore confinement effect in electrochemistry. Redox ; Microporous material ; Adsorption ; Electrochemistry ; Chemical engineering ; Electrolyte ; Half-reaction ; Molecule ; Chemistry ; Quinone ; Materials science ; Inorganic chemistry ; Electrode ; Physical chemistry ; Organic chemistry Conducting polymers and applications ; Electrochemical Analysis and Applications ; Advanced battery technologies research
Authors: Atul Atul | Majid Ahmadi | Panagiotis Koutsogiannis | Heng Zhang | Bart J. Kooi
Source: Advanced Materials Interfaces (article, 2023-12-11)
Field: Materials Science — Polymers and Plastics

Strong Substrate Influence on Atomic Structure and Properties of Epitaxial VO<sub>2</sub> Thin Films Abstract The metal–insulator transition (MIT) observed in vanadium dioxide has been a topic of great research interest for past decades, with the underlying physics yet not fully understood due to the complex electron interactions and structures involved. The ability to understand and tune the MIT behavior is of vital importance from the perspective of both underlying fundamental science as well as potential applications. In this work, scanning transmission electron microscopy (STEM) is used to investigate cross‐section lamella of the VO 2 films deposited using pulsed laser deposition on three substrates: c‐cut sapphire, TiO 2 (101) and TiO 2 (001). Advanced STEM imaging is performed in which also the oxygen atom columns are resolved. The overall film quality and structures on atomic and nanoscale are linked to the electrical transition characteristics. Relatively poor MIT characteristics are observed on c‐sapphire due to the presence of very small domains with six orientation variants, and on TiO 2 (001) due to the presence of cracks induced by stress relaxation. However, the MIT on TiO 2 (101) behaves favorably, despite similar stress relaxation which, however, only leads to domain boundaries but no cracks. Materials science ; Scanning transmission electron microscopy ; Sapphire ; Pulsed laser deposition ; Thin film ; Atomic units ; Epitaxy ; Kelvin probe force microscope ; Transmission electron microscopy ; Chemical physics ; Substrate (aquarium) ; Nanotechnology ; Nanoscopic scale ; Crystallography ; Atomic force microscopy ; Laser ; Optics Transition Metal Oxide Nanomaterials ; Ga2O3 and related materials ; ZnO doping and properties
Authors: Xiaodong Nie | Xiangyun Wu | Yi Zhi | Zhilin Long | Hui Sheng Zhou | Nan Ji
Source: Materials (article, 2023-04-25)
Field: Materials Science — Materials Chemistry

Discussion on Static Resistance of Granite under Penetration A total of 9 tests were carried out with 30 mm and 78 mm caliber scaled projectiles penetrating into granite targets. The penetration depth, crater diameter, and mass loss rate were examined and discussed. The results indicate that the dimensionless penetration depth of large-caliber projectiles is 20% greater than small-caliber projectiles. Based on the description of static resistance <i>R<sub>a</sub></i> in the Forrestal semi-empirical formula, the size effect of dimensionless penetration depth can be attributed to the size effect of static resistance <i>R<sub>a</sub></i>, and it can be seen that the penetration static resistance of projectile A is 40% higher than that of projectile B. Numerical simulations of projectile penetration into granite targets were conducted using the finite element program ANSYS/LS-DYNA. In terms of penetration depth and crater damage, the numerical simulation results agree well with the test data. This suggests that the selection of parameters was reasonable. The influence of compressive strength, projectile striking velocity, mass, diameter, and caliber-radius-head (CRH) ratio on the static resistance <i>R<sub>a</sub></i> were studied by RHT model parameterization. Based on the numerical results from the parametric study, an empirical formula was derived to predict the static resistance <i>R<sub>a</sub></i>. Penetration (warfare) ; Geotechnical engineering ; Materials science ; Composite material ; Resistance (ecology) ; Geology ; Forensic engineering ; Engineering ; Operations research ; Biology ; Agronomy High-Velocity Impact and Material Behavior ; Rock Mechanics and Modeling ; Geophysical Methods and Applications