jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Genhao Liang | Hui Cao | Long Cheng | Junkun Zha | Mingrui Bao | Fei Ye | Hua Zhou | Aidi Zhao | Xiaofang Zhai
Source: Chinese Physics B (article, 2024-06-07)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Simultaneous control of ferromagnetism and ferroelasticity by oxygen octahedral backbone stretching Abstract Coexistence of ferromagnetism and ferroelasticity in a single material is an intriguing phenomenon, but has been rarely found. Here we studied both the ferromagnetism and ferroelasticity in a group of LaCoO 3 films with systematically tuned atomic structures. We found that all films exhibit ferroelastic domains with four-fold symmetry and the larger domain size (higher elasticity) is always accompanied by stronger ferromagnetism. We performed synchrotron x-ray diffraction studies to investigate the backbone structure of the CoO 6 octahedra, and found that both the ferromagnetism and the elasticity are simultaneously enhanced when the in-plane Co–O–Co bond angles are straightened. Therefore the study demonstrates the inextricable correlation between the ferromagnetism and ferroelasticity mediated through the octahedral backbone structure, which may open up new possibilities to develop multifunctional materials. Ferroelasticity ; Ferromagnetism ; Octahedron ; Crystallography ; Condensed matter physics ; Chemistry ; Materials science ; Crystal structure ; Ferroelectricity ; Physics Magnetic and transport properties of perovskites and related materials ; Multiferroics and related materials ; Magnetic properties of thin films
Authors: Tourya Khlifi | Chaimae Jbilou | Alexis Leblais | Jérôme Marrot | Pierrick Nun | Clément Ghiazza | Isabelle Chataigner | Vincent Coeffard | Xavier Moreau
Source: Organic Letters (article, 2024-07-29)
Field: Chemistry — Organic Chemistry

Atroposelective Construction of Axially Chiral 2-Aryl-Pyrroloquinolones A two-step protocol including an enantioselective organocatalyzed synthesis of pyrroloquinolines followed by an oxidation reaction allowed the formation of axially chiral 2-aryl-pyrroloquinolones. Thorough optimization of the experimental conditions for the second step allowed the oxygenation reaction to take place and ensured, in most cases, a central-to-axial chirality conversion with complete retention of the enantiomeric excess. Axial symmetry ; Chemistry ; Enantioselective synthesis ; Axial chirality ; Aryl ; Enantiomer ; Enantiomeric excess ; Combinatorial chemistry ; Catalysis ; Chirality (physics) ; Computational chemistry ; Organic chemistry ; Geometry Axial and Atropisomeric Chirality Synthesis ; Molecular spectroscopy and chirality ; Biological Activity of Diterpenoids and Biflavonoids
Authors: Juan Gomez Quispe | Douglas S. Galvão | Pedro Alves da Silva Autreto
Source: ACS Omega (article, 2024-12-11)
Field: Materials Science — Materials Chemistry

Exploring the Electronic and Mechanical Properties of TPDH Nanotube: Insights from Ab Initio and Classical Molecular Dynamics Simulations Tetra-Penta-Deca-Hexa graphene (TPDH) is a new two-dimensional (2D) carbon allotrope with attractive electronic and mechanical properties. It is composed of tetragonal, pentagonal, decagonal and hexagonal carbon rings. When TPDH graphene is sliced into quasi-one-dimensional (1D) structures such as nanoribbons, it exhibits a range of behaviors, from semimetallic to semiconducting. An alternative approach to achieving these desirable electronic properties (electronic confinement and nonzero electronic band gap) is the creation of nanotubes (TPDH-NTs). In the present work, we carried out a comprehensive study of TPDH-NTs combining Density Functional Theory (DFT) and classical reactive Molecular Dynamics (MD). Our results show structural stability and a chiral dependence on the mechanical properties. Similarly to standard carbon nanotubes, TPDH-NT can be metallic or semiconductor. MD results show Young's modulus values exceeding 700 GPa, except for nanotubes with very small radii. However, certain chiral TPDH-NTs (<i>n</i>, <i>m</i>) display values both below and above 700 GPa, particularly for those with small radii. Analysis of the evolution of von Mises stress and the distribution of C-C bond angles and lengths throughout the stress-strain process indicates the important role of tetragonal, pentagonal, and hexagonal rings for the mechanical response of TPDH-NTs. Tetragonal and pentagonal rings provide a rigid mechanical framework for TPDH-NTs (<i>n</i>, 0), whereas pentagonal and hexagonal rings provide TPDH-NTs (0, <i>n</i>) with greater flexibility. Ab initio ; Nanotube ; Molecular dynamics ; Materials science ; Dynamics (music) ; Ab initio quantum chemistry methods ; Electronic structure ; Nanotechnology ; Chemical physics ; Computational chemistry ; Statistical physics ; Carbon nanotube ; Physics ; Chemistry ; Quantum mechanics ; Molecule Boron and Carbon Nanomaterials Research ; Graphene research and applications ; Advanced Thermoelectric Materials and Devices
Authors: Shagun Sharma | Aditya Yadav | Kush Kaushik | Abdul Salam | Chayan Kanti Nandi
Source: Nanoscale (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Assessing the overflowing pile-up effect on the photoluminescence lifetime of nanomaterials The tunable complex emissive states with nanosecond to microsecond lifetimes in nanomaterials, arise due to their structural heterogeneity, enabling them with a wide range of advanced optoelectronic applications. However, understanding the complex photoluminescence lifetime in these nanomaterials is critically challenged by the overflowing pile-up effect, which occurs due to the high repetition rate of the light source in the time-correlated single photon counting (TCSPC) technique. Here, we provide a quantitative lifetime analysis, especially in metal nanoclusters, metal complexes, and semiconductor quantum dots, which suggests that the same experimental parameters can mislead the lifetime data interpretation for long-ranged luminescent nanomaterials. We demonstrate that the overflowing pile-up effect could be fatal while analyzing the excited state lifetime. Furthermore, we provide the optimized parameters that could be used to get the actual lifetime data of samples. We hope that our findings will be crucial in obtaining the error-free and accurate excited state dynamics of these long-range lifetime nanomaterials. Nanomaterials ; Photoluminescence ; Pile ; Materials science ; Nanotechnology ; Environmental chemistry ; Chemistry ; Geology ; Optoelectronics ; Geotechnical engineering Nanocluster Synthesis and Applications ; Gold and Silver Nanoparticles Synthesis and Applications ; Carbon and Quantum Dots Applications
Authors: Ch. Ferrer‐Roca | Julio Pellicer‐Porres | A. Segura | V. Panchal | D. Kim | P. Rodríguez‐Hernández | Alfonso Muñoz | A. Polian
Source: Physical review. B./Physical review. B (article, 2024-09-27)
Field: Materials Science — Materials Chemistry

Fourier transform infrared investigation of dielectric and lattice dynamical properties of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>CuAlO</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> delafossite under high pressure This paper reports an investigation of the pressure dependence of lattice-dynamical and dielectric properties of ${\mathrm{CuAlO}}_{2}$ delafossite by means of Fourier transform infrared spectroscopy and ab initio calculations. The availability of single-crystal and powdered samples allowed for an almost complete characterization of the pressure behavior of polar phonons and dielectric function from the far-infrared to the near-ultraviolet spectral range. The pressure-induced increase of the electronic contribution to the dielectric constant for polarization perpendicular to the $c$ axis is fully accounted for by volume reduction, showing that the electronic polarizability remains virtually constant under pressure. The behavior of the polar phonon contribution to the static dielectric constant is more complex. The contribution of the high-frequency ${E}_{u,\mathrm{TO}}^{h}$ mode $(489 \mathrm{c}{\mathrm{m}}^{\ensuremath{-}1})$, with positive pressure coefficient, slightly decreases under pressure. On the opposite, the contribution of the low-frequency ${E}_{u,\mathrm{TO}}^{l}$ mode (143 $\mathrm{c}{\mathrm{m}}^{\ensuremath{-}1}$ at ambient pressure) largely increases as it becomes softer under pressure, leading to an overall increase of the static dielectric constant. For polarization parallel to the $c$ axis, the electronic contribution is insensitive to pressure. The polar mode ${A}_{2u,\mathrm{TO}}^{h}$ (700 $\mathrm{c}{\mathrm{m}}^{\ensuremath{-}1}$) has positive pressure coefficient. Then, an overall decrease of the static dielectric constant for polarization parallel to the $c$ axis is expected. Fourier transform ; Lattice (music) ; Dielectric ; Computer science ; Mathematics ; Physics ; Mathematical analysis ; Optoelectronics Copper-based nanomaterials and applications ; ZnO doping and properties ; Magnesium Oxide Properties and Applications
Authors: Bhushan Karmkar | Reshma Mokal | Sudarshan Landge | Bhushan Jadhav
Source: International Journal for Research in Applied Science and Engineering Technology (review, 2024-05-26)
Field: Materials Science — Polymers and Plastics

Design and Implement a BTMS using Phase Change Material - A Review Abstract: This paper presents a comprehensive review of the design and implementation of Battery Thermal Management Systems (BTMS) utilizing Phase Change Materials (PCM). The thermal management of batteries is crucial for ensuring optimal performance, safety, and longevity, particularly in electric vehicles and renewable energy storage applications. Phase change materials offer unique advantages for thermal management, including high latent heat storage capacity, thermal conductivity, and temperature regulation capabilities. This review discusses the fundamentals of PCM-based BTMS design, including PCM selection, integration methods, and system optimization techniques. Additionally, recent advancements, challenges, and future directions in PCM-based BTMS are explored, providing valuable insights for researchers, engineers, and industry practitioners in the field of energy storage systems. Phase (matter) ; Computer science ; Phase change ; Engineering ; Chemistry ; Engineering physics Synthesis and properties of polymers
Authors: K.M. El-Kourghly
Source: Scientific Reports (article, 2024-12-31)
Field: Materials Science — Materials Chemistry

Absolute calibration methodology for non-uniform uranium and matrix distributions in large barrels of uranium-bearing solid waste The effective implementation of domestic and international safeguards necessitates verification techniques for Nuclear Materials (NM). Even in the case of very small quantities of NMs, accounting for and analyzing such traces can provide insights into the mass balance of NMs and/or state activities, ensuring consistency in state declarations. This paper proposes and benchmarks an absolute calibration methodology for estimating the uranium-mass content in large-volume barrels (200 L). These barrels may be generated during the operation and decommissioning of bulk handling facilities by accumulating low-density scarab contaminated with NMs. The method relies on the mathematical calibration of a High Purity Germanium (HPGe) detector efficiency against non-uniform uranium and matrix distributions, assuming that the non-uniform distribution can be approximated as a uniform one for low-density matrix materials. The peak efficiency is calculated for different numbers of point sources 1-30 likely distributed inside a simulated barrel while it rotates around the axis of symmetry. The proposed method is benchmarked by comparing the calculated peak efficiency of randomly distributed uranium sources with the homogeneous distribution. Furthermore, a comparison with experimental measurements is conducted to validate the proposed method. Results show that the proposed calibration method considering either random or homogeneous source and matrix distributions in large volume barrels can be used for estimating the uranium mass content in NSW with an accuracy of approximately 12 %. Uranium ; Bearing (navigation) ; Calibration ; Matrix (chemical analysis) ; Radioactive waste ; Nuclear engineering ; Environmental science ; Municipal solid waste ; Waste management ; Materials science ; Computer science ; Mathematics ; Engineering ; Composite material ; Metallurgy ; Statistics Nuclear materials and radiation effects ; Nuclear Materials and Properties ; Radioactivity and Radon Measurements
Authors: Lukas Hellbrück | Michele Puppin | Fei Guo | Daniel D. Hickstein | S. Benhabib | M. Grioni | J. Hugo Dil | Thomas LaGrange | H. M. Rønnow | Fabrizio Carbone
Source: Review of Scientific Instruments (preprint, 2024-03-01)
Field: Chemistry — Spectroscopy

High-resolution MHz time- and angle-resolved photoemission spectroscopy based on a tunable vacuum ultraviolet source The time- and angle-resolved photoemission spectroscopy (trARPES) allows for direct mapping of the electronic band structure and its dynamic response on femtosecond timescales. Here, we present a new ARPES system, powered by a new fiber-based femtosecond light source in the vacuum ultraviolet range, accessing the complete first Brillouin zone for most materials. We present trARPES data on Au(111), polycrystalline Au, Bi2Se3, and TaTe2, demonstrating an energy resolution of 21 meV with a time resolution of <360 fs, at a high repetition rate of 1 MHz. The system is integrated with an extreme ultraviolet high harmonic generation beamline, enabling an excellent tunability of the time-bandwidth resolution. Vacuum ultraviolet ; Ultraviolet ; Photoemission spectroscopy ; Angle-resolved photoemission spectroscopy ; Inverse photoemission spectroscopy ; Spectroscopy ; Materials science ; Optoelectronics ; Resolution (logic) ; Optics ; Physics ; X-ray photoelectron spectroscopy ; Nuclear magnetic resonance ; Spectral line ; Computer science ; Astronomy Spectroscopy and Laser Applications ; Photocathodes and Microchannel Plates ; Laser Design and Applications
Authors: Tjerk R. Watt | K. van Dijk | Esra te Brinke | Joris de Grooth | Wiebe M. de Vos
Source: Advanced Materials Technologies (article, 2024-12-27)
Field: Materials Science — Surfaces, Coatings and Films

Going from Inner‐Skinned to Outer‐Skinned Polyelectrolyte Multilayer Based Hollow Fiber Nanofiltration Membranes Abstract Recently, hollow fiber polyelectrolyte multilayer membranes (PEMMs) have shown great potential for removing organic micropollutants from wastewater streams. Currently, these PEMMs are made with the selective layer on the inside of the hollow fiber. However, to reduce the physical footprint of PEMM modules, it would be beneficial to have the selective layer on the outside. This will lead to an increased surface area per fiber and enable the use of smaller mechanically stronger fibers, which further increases the surface area per membrane module. To prove that the concept of an outer‐skinned PEMM is feasible, the dry‐jet wet‐spinning process is used to fabricate charged outer‐skinned hollow fiber supports, and they are coated through the layer‐by‐layer self‐assembly process to form a PEMM. Scanning electron microscopy images of the hollow fibers confirm the existence of an asymmetric structure with an outer skin, while fluorescence imaging confirms that the polyelectrolyte multilayer is located on the outside of the hollow fiber. Filtration experiments showed that the PEMMs exhibited nanofiltration properties similar to the conventional inner‐skinned PEMMs. Overall, these membranes show a 3.8x increase in active membrane surface area to volume ratio compared to commercial PEMMs, clearly highlighting the benefits in terms of footprint. Nanofiltration ; Polyelectrolyte ; Membrane ; Materials science ; Fiber ; Chemical engineering ; Chemistry ; Composite material ; Polymer ; Engineering Polymer Surface Interaction Studies ; Membrane Separation Technologies ; Surface Modification and Superhydrophobicity
Authors: Ke Huang | S. Das Sarma | Xiao Li
Source: arXiv (Cornell University) (preprint, 2024-09-06)
Field: Materials Science — Materials Chemistry

Impurity-induced thermal crossover in fractional Chern insulators The recent experimental observation of fractional quantum anomalous Hall (FQAH) states in rhombohedral multilayer graphene has attracted significant attention. One of the most intriguing observations is that the FQAH states at various fractional fillings give way to IQAH states as the temperature is lowered. In this work, we propose a mechanism for the appearance of FQAH states within a finite temperature range in a toy model. The model consists of a flat Chern band and impurities, and we analyze the effects of impurities on the system's behavior at finite temperatures. We believe that the crossover may arise from the competition between the energy penalty for thermal excitations and the increase in entropy. We support our theoretical argument with numerical calculations using exact diagonalization. Our results suggest that impurities may play a crucial role in the crossover from the FQAH to IQAH states in rhombohedral pentalayer graphene. Crossover ; Impurity ; Thermal ; Condensed matter physics ; Materials science ; Physics ; Quantum mechanics ; Thermodynamics ; Computer science Thermal properties of materials ; Quantum and electron transport phenomena ; Optical properties and cooling technologies in crystalline materials
Authors: Ye Wang | Yongyi Chen | Li Qin | Lijun Wang
Source: Micromachines (article, 2024-10-23)
Field: Materials Science — Surfaces, Coatings and Films

Optimal Design and Analysis of Wide-Band Near-Infrared Hybrid Dielectric Gratings with High Transmission Efficiency Since surface relief transmission gratings have very strict requirements on operators and use environment, according to the semiconductor laser external cavity spectral beam combining system, this paper proposes a design scheme for a semiconductor laser array spectral beam combining system based on the grating-external cavity. The finite element approach was used to create a wideband, high-efficiency fill-in multilayer dielectric transmission grating structure for a high-power spectrum beam combining system. The incidence angle, ridge height, duty cycle, and sidewall inclination angle of the transmission grating were tuned and evaluated, and a link between the transmission grating's diffraction efficiency and grating characteristics was discovered. The calculated design of the high-power fused silica transmission grating has a negative first-order peak diffraction efficiency of 99.5% in the 800 nm range. In the spectral region of 765-872 nm, the transmission grating's diffraction effectiveness exceeds 92%. The filled ultra-high diffraction efficiency multilayer dielectric transmission grating design addresses the issue of resistance to high-power lasers under complicated operating settings. It is intended to maintain a high diffraction efficiency even after several cleaning cycles, and it is an ideal component for high-power spectrum beam combining systems. Materials science ; Dielectric ; Infrared ; Transmission (telecommunications) ; Optoelectronics ; Optics ; Electronic engineering ; Telecommunications ; Computer science ; Physics ; Engineering Optical Coatings and Gratings ; Photonic and Optical Devices ; Photonic Crystals and Applications
Authors: Yi‐Wen Liu | Ambikesh Gupta | Youngjoon Choi | Yaar Vituri | Hari Stoyanov | Jiewen Xiao | Yanzhen Wang | Haibiao Zhou | Barun Barick | Takashi Taniguchi | Kenji Watanabe | Binghai Yan | Erez Berg | Andrea F. Young | Haim Beidenkopf | Nurit Avraham
Source: arXiv (Cornell University) (preprint, 2024-11-17)
Field: Materials Science — Materials Chemistry

Visualizing incommensurate inter-valley coherent states in rhombohedral trilayer graphene ABC-stacked rhombohedral graphene multilayers exhibit a wide variety of electronic ground states characterized by broken isospin symmetry and superconductivity. Recently, indirect evidence of inter-valley coherent (IVC) order has been reported in rhombohedral trilayer graphene (RTG), with possible implications for the origin of superconductivity. Here, we report the direct visualization of IVC order in RTG using scanning tunneling microscopy and spectroscopy. Tuning the chemical potential through the Van Hove singularity near the edge of the valence band, we observe a cascade of phase transitions associated with the formation of half- and quarter-metal states. IVC phases, distinguished by an enlarged real space unit cell, are directly imaged near both the high- and low-density boundaries of the half-metal phase. At high hole density, we precisely reconstruct the IVC band structure through quasiparticle interference. Intriguingly, the charge density modulations reveal a C3-symmetric incommensurate IVC order that agrees with the recent prediction of an IVC-crystal phase. Our findings demonstrate that IVC phases are a widespread symmetry-broken ground state within graphene systems. Trigonal crystal system ; Graphene ; Condensed matter physics ; Materials science ; Physics ; Nanotechnology ; Crystallography ; Chemistry ; Crystal structure Graphene research and applications
Authors: H. Hammami | Chahra Amairia
Source: Advanced Theory and Simulations (article, 2024-12-10)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Realistic Estimation of Critical Exponents for Predicting the Magnetocaloric Effect in La<sub>0.7</sub>Sr<sub>0.3–x</sub>Sm<sub>x</sub>Mn<sub>0.95</sub>Ni<sub>0.05</sub>O<sub>3</sub> (x = 0, 0.05, 0.10, 0.15) Manganites Abstract In this article, is introduce a calculation approach derived from integrating the Landau theory with the Arrott–Noakes equation. Employing a creative formulation, is conduct simulations to explore the magnetic entropy change, within a random ferromagnetic system. This theoretical approach is used for the examination of a given La 0.7 Sr 0.3–x Sm x Mn 0.95 Ni 0.05 O 3 (x = 0, 0.05, 0.10, 0.15) manganites. Initially, the critical exponents (𝛾; 𝛽) of these compounds are estimated. It has been noted that the magnetic behavior of the examined materials near the phase transition deviate from the standard patterns observed in typical universality classes. Subsequently, these exponents are exploited to simulate the isothermal curves under higher magnetic fields. The predicted relative cooling power values reach 420.3, 415.7, 412.5, and 408.4 J.kg −1 K −1 under 10 T applied magnetic field for La 0.7 Sr 0.3–x Sm x Mn 0.95 Ni 0.05 O 3 with x = 0, 0.05, 0.10 and 0.15, respectively. Magnetic refrigeration ; Critical exponent ; Isothermal process ; Ferromagnetism ; Condensed matter physics ; Phase transition ; Exponent ; Universality (dynamical systems) ; Thermodynamics ; Landau theory ; Magnetic field ; Materials science ; Physics ; Magnetization ; Quantum mechanics Magnetic and transport properties of perovskites and related materials ; Shape Memory Alloy Transformations ; Advanced Thermoelectric Materials and Devices