jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Xianyuan Liu | Xianghua Wang | Xianyong Lu | Lei Jiang
Source: Small (article, 2024-12-20)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Localized Morphological Modulation of Ultrathin Magnetic Nanosheets via a Strategically Designed Reduction Approach 2D inorganic nanomaterials have attracted considerable research interest owing to their exceptional physical and chemical properties. Nonetheless, achieving precise control over the morphology of 2D nanomaterials presents a significant challenge, primarily due to their elevated surface energy and the stringent requirements for growth control. In this study, a designed reduction technique is employed to finely tune the morphology of 2D nanosheets, with iron salts serving as morphology-directing agents. Al-doped α-Fe<sub>2</sub>O<sub>3</sub> nanosheets are synthesized through a solvothermal process and subsequently reduced to Al-doped Fe<sub>3</sub>O<sub>4</sub> nanosheets, characterized by distinctive sawtooth-like edges. The incorporation of iron salts facilitates atomic rearrangement within the iron oxide lattice, wherein rapid atomic migration induces defects along the crystal facets, resulting in unique morphologies. Furthermore, the doping of aluminum elements and the resultant Fe<sub>3</sub>O<sub>4</sub> significantly enhance the electromagnetic properties of the nanosheets, yielding exceptional electromagnetic wave absorption performance. Notably, a remarkable minimum reflection loss (RL<sub>min</sub>) of -66.1 dB is achieved at a thickness of 4.0 mm, with an effective absorption bandwidth (RL ≤ -10 dB) extending up to 3.9 GHz. This controlled reduction strategy presents a promising pathway for tailoring the morphology of 2D nanomaterials and optimizing their performance in electromagnetic wave absorption applications. Nanomaterials ; Materials science ; Reflection loss ; Nanotechnology ; Doping ; Absorption (acoustics) ; Iron oxide ; Chemical engineering ; Optoelectronics ; Composite number ; Composite material ; Metallurgy Electromagnetic wave absorption materials ; Advanced Antenna and Metasurface Technologies ; Metamaterials and Metasurfaces Applications
Authors: A. V. Motorzhina | Stanislav Pshenichnikov | А. А. Аникин | V. K. Belyaev | Alexander N. Yakunin | Sergey V. Zarkov | Valery V. Tuchin | Sonja Jovanović | Claudio Sangregorio | Valeria Rodionova | L.V. Panina | Kateryna Levada
Source: Journal of Biophotonics (article, 2024-06-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Gold/cobalt ferrite nanocomposite as a potential agent for photothermal therapy The study encompasses an investigation of optical, photothermal and biocompatibility properties of a composite consisting of golden cores surrounded by superparamagnetic CoFe<sub>2</sub>O<sub>4</sub> nanoparticles. Accompanied with the experiment, the computational modeling reveals that each adjusted magnetic nanoparticle redshifts the plasmon resonance frequency in gold and nonlinearly increases the extinction cross-section at ~800 nm. The concentration dependent photothermal study demonstrates a temperature increase of 8.2 K and the photothermal conversion efficiency of 51% for the 100 μg/mL aqueous solution of the composite nanoparticles, when subjected to a laser power of 0.5 W at 815 nm. During an in vitro photothermal therapy, a portion of the composite nanoparticles, initially seeded at this concentration, remained associated with the cells after washing. These retained nanoparticles effectively heated the cell culture medium, resulting in a 22% reduction in cell viability after 15 min of the treatment. The composite features a potential in multimodal magneto-plasmonic therapies. Photothermal therapy ; Superparamagnetism ; Materials science ; Biocompatibility ; Nanoparticle ; Photothermal effect ; Surface plasmon resonance ; Nanocomposite ; Composite number ; Nanotechnology ; Chemical engineering ; Composite material ; Magnetization ; Magnetic field ; Metallurgy Gold and Silver Nanoparticles Synthesis and Applications ; Nanoplatforms for cancer theranostics ; Laser-Ablation Synthesis of Nanoparticles
Authors: Marwa Adel | Dina Hassan | Marwa A. A. Mohamed | Taher S. Kassem | Howida A. Fetouh | S.E. AbdElhafez | Jehan El Nady
Source: Scientific Reports (article, 2024-11-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Role of synthetic process parameters of nano-sized cobalt/nickel oxide in controlling their structural characteristics and electrochemical energy performance as supercapacitor electrodes The synthesis of nano-sized bimetallic Cobalt/Nickel oxides (Ni<sub>1.5</sub>Co<sub>1.5</sub>O<sub>4</sub>) with a 1:1 Co/Ni atomic ratio has been achieved using a surfactant-free co-precipitation/hydrothermal process. The growth mechanism of Cobalt/Nickel oxides Ni<sub>1.5</sub>Co<sub>1.5</sub>O<sub>4</sub> is elucidated by tuning the synthesis process parameters, including co-precipitation pH and hydrothermal time. The formation of Cobalt/Nickel oxides Ni<sub>1.5</sub>Co<sub>1.5</sub>O<sub>4</sub> oxide began with the nucleation of cobalt nickel hydroxide nanoplates through the co-precipitation process, followed by dissolution-recrystallization, stacked hexagonal nano-flakes, and a flower-like microstructure. The electrochemical performances of the oxides were evaluated, with the largest surface area observed at pH 9 being the main factor for the best super-capacitive performance. As hydrothermal time increased, the structural directing growth forward, resulted in the formation of a nano-flower structure with a larger surface area. The as-prepared cobalt nickel oxide exhibited a maximum specific capacitance value of 525.5 F g<sup>-1</sup> at a current density of 1 A g<sup>-1</sup> and energy and power densities of 88.2 WhKg<sup>-1</sup> and 606 WKg<sup>-1</sup>, respectively. Supercapacitor ; Electrochemistry ; Cobalt ; Cobalt oxide ; Materials science ; Electrode ; Nickel ; Nano- ; Oxide ; Process (computing) ; Nickel oxide ; Nanotechnology ; Chemical engineering ; Metallurgy ; Computer science ; Chemistry ; Composite material Supercapacitor Materials and Fabrication ; Advancements in Battery Materials ; Catalytic Processes in Materials Science
Authors: Anna P. Yi | Oleg G. Salnikov | Dudari B. Burueva | Nikita V. Chukanov | Eduard Y. Chekmenev | Igor V. Koptyug
Source: ChemRxiv (preprint, 2024-03-12)
Field: Chemistry — Spectroscopy

Solvent effects in hyperpolarization of 15N nuclei in [15N3]metronidazole and [15N3]nimorazole antibiotics via SABRE-SHEATH Metronidazole and nimorazole are antibiotics of a nitroimidazole group originally designed for acting on anaerobic bacteria. These antibiotics may be potentially utilized as hypoxia radiosensitizers for the treatment of cancerous tumors. Hyperpolarization of 15N nuclei in these compounds using SABRE-SHEATH (Signal Amplification By Reversible Exchange in SHield Enables Alignment Transfer to Heteronuclei) approach provides dramatic enhancement of detection sensitivity of these analytes using magnetic resonance spectroscopy and imaging. Methanol-d4 is conventionally employed as a solvent in SABRE hyperpolarization process. Herein, we investigate SABRE-SHEATH hyperpolarization of isotopically labeled [15N3]metronidazole and [15N3]nimorazole in nondeuterated methanol-h4 and ethanol-h6 solvents (with the latter one being more preferable for biomedical applications due to its significantly lower toxicity). Optimization of hyperpolarization parameters, such as polarization transfer magnetic field, temperature, parahydrogen flow rate and pressure, allowed us to obtain an average 15N polarization of up to ca. 7.6% for both substrates. The highest 15N polarizations were observed in methanol-d4 for [15N3]metronidazole and in ethanol-h6 for [15N3]nimorazole. At a clinically relevant magnetic field of 1.4 T the 15N nuclei of these substrates possess long characteristic hyperpolarization lifetimes (T1) in the range from ca. 1 to ca. 7 min, with the longest relaxation observed for 15NO2 sites. This study represents a major step toward SABRE in more biocompatible solvents, such as ethanol, and also paves the way for future utilization of these hyperpolarized nitroimidazoles as molecular contrast agents for MRI visualization of tumors. Hyperpolarization (physics) ; Metronidazole ; Chemistry ; Antibiotics ; Solvent ; Nuclear magnetic resonance ; Nuclear magnetic resonance spectroscopy ; Physics ; Stereochemistry ; Biochemistry Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography ; Radiation Detection and Scintillator Technologies
Authors: Christoph Scherer | Naomi Kinaret | Kun‐Han Lin | Muhammad Nawaz Qaisrani | F. Post | Falk May | Denis Andrienko
Source: Advanced Energy Materials (article, 2024-09-29)
Field: Materials Science — Materials Chemistry

Predicting Molecular Ordering in Deposited Molecular Films Abstract Thin films of molecular materials are commonly employed in organic light‐emitting diodes, field‐effect transistors, and solar cells. The morphology of these organic films is shown to depend heavily on the processing used during manufacturing, such as vapor co‐deposition. However, the prediction of processing‐dependent morphologies has until now posed a significant challenge, particularly in cases where self‐assembly and ordering are involved. In this work, a method is developed based on coarse‐graining that is capable of predicting molecular ordering in vapor‐deposited films of organic materials. The method is tested on an extensive database of novel and known organic semiconductors. A good agreement between the anisotropy of the refractive indices of the simulated and experimental vapor‐deposited films suggests that the method is quantitative and can predict the molecular orientations in organic films at an atomistic resolution. The methodology can be readily utilized for screening materials for organic light‐emitting diodes. Materials science ; Nanotechnology ; Chemical engineering ; Chemical physics Machine Learning in Materials Science ; Molecular Junctions and Nanostructures ; Advanced Chemical Physics Studies
Authors: Zaifa Yang
Source: Molecules (article, 2024-09-07)
Field: Materials Science — Materials Chemistry

Efficient and Near-Zero Thermal Quenching Cr3+-Doped Garnet-Type Phosphor for High-Performance Near-Infrared Light-Emitting Diode Applications In recent years, near-infrared (NIR) phosphors have attracted great research interest due to their unique physical properties and broad application prospects. However, obtaining NIR phosphors with both high quantum efficiency and excellent thermal stability remains a great challenge. In this study, novel NIR Ca<sub>3</sub>Mg<sub>2</sub>ZrGe<sub>3</sub>O<sub>12</sub>:Cr<sup>3+</sup> phosphors were successfully prepared using a high-temperature solid-phase method, and the structure and luminescent properties of the material were systematically investigated. Ca<sub>3</sub>Mg<sub>2</sub>ZrGe<sub>3</sub>O<sub>12</sub>:0.01Cr<sup>3+</sup> emits NIR light in the range of 600 to 900 nm with a peak at 758 nm and a half-height width of 89 nm under the excitation of 457 nm blue light. NIR luminescence shows considerable quantum efficiency, and the internal quantum efficiency of the optimized sample is up to 68.7%. Remarkably, the Ca<sub>3</sub>Mg<sub>2</sub>ZrGe<sub>3</sub>O<sub>12</sub>:0.01Cr<sup>3+</sup> phosphor exhibits a near-zero thermal quenching behavior, and the luminescence intensity of the sample at 250 °C maintains 92% of its intensity at room temperature. The mechanism of high thermal stability has been elucidated by calculating the Huang Kun factor and activation energy. Finally, NIR pc-LED devices prepared from Ca<sub>3</sub>Mg<sub>2</sub>ZrGe<sub>3</sub>O<sub>12</sub>:0.01Cr<sup>3+</sup> phosphor with commercial blue LED chips have good performance, proving that this Ca<sub>3</sub>Mg<sub>2</sub>ZrGe<sub>3</sub>O<sub>12</sub>:0.01Cr<sup>3+</sup> NIR phosphor has potential applications in night vision and biomedical imaging. Phosphor ; Materials science ; Quantum efficiency ; Thermal stability ; Luminescence ; Optoelectronics ; Light-emitting diode ; Diode ; Near-infrared spectroscopy ; Quenching (fluorescence) ; Doping ; Infrared ; Analytical Chemistry (journal) ; Optics ; Fluorescence ; Chemistry ; Physics Luminescence Properties of Advanced Materials ; Perovskite Materials and Applications ; Luminescence and Fluorescent Materials
Authors: Kaijun Shen | Kewei Sun | Maxim F. Gelin | Yang Zhao
Source: Materials (article, 2024-08-20)
Field: Materials Science — Materials Chemistry

Cavity-Tuned Exciton Dynamics in Transition Metal Dichalcogenides Monolayers A fully quantum, numerically accurate methodology is presented for the simulation of the exciton dynamics and time-resolved fluorescence of cavity-tuned two-dimensional (2D) materials at finite temperatures. This approach was specifically applied to a monolayer WSe2 system. Our methodology enabled us to identify the dynamical and spectroscopic signatures of polaronic and polaritonic effects and to elucidate their characteristic timescales across a range of exciton-cavity couplings. The approach employed can be extended to simulation of various cavity-tuned 2D materials, specifically for exploring finite temperature nonlinear spectroscopic signals. Monolayer ; Exciton ; Transition metal ; Materials science ; Chemical physics ; Nanotechnology ; Metal ; Dynamics (music) ; Condensed matter physics ; Optoelectronics ; Chemistry ; Physics ; Metallurgy 2D Materials and Applications ; Strong Light-Matter Interactions ; Perovskite Materials and Applications
Authors: Naveena Gadwala
Source: physica status solidi (b) (article, 2024-09-29)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Effect of Trivalent Ho<sup>3+</sup> Ion Doping on Structural, Magnetic, Optical, and Electrical Properties of BiFeO<sub>3</sub> Nanoparticles Holmium (Ho)‐doped bismuth ferrite (BiFeO 3 ) nanoparticles are synthesized using the citrate‐gel autocombustion method to investigate their structural, dielectric, ferroelectric, and magnetic properties. X‐Ray diffraction analysis confirms the formation of a rhombohedral perovskite structure, with crystalline size decreasing from ≈14 to 7 nm as doping levels increase. Fourier‐transform infrared spectroscopy further validates the perovskite phase, while field emission scanning electron microscopy and energy‐dispersive X‐Ray spectroscopy confirm the nanocrystalline nature and composition of the samples. X‐Ray photoelectron spectroscopy verifies the successful incorporation of Ho 3+ ions into the BiFeO 3 matrix. The dielectric properties show high permittivity and low dielectric losses, while magnetic hysteresis loops reveal enhanced magnetic properties, including increased saturation magnetization, remanence, coercivity, squareness ratio, Bohr magneton, and magnetocrystalline anisotropy. These findings indicate that Ho‐doped BiFeO 3 nanoparticles exhibit significantly improved electric and magnetic performance, positioning them as promising candidates for applications in magnetic storage devices and sensors. Doping ; Materials science ; Nanoparticle ; Ion ; Condensed matter physics ; Crystallography ; Inorganic chemistry ; Nanotechnology ; Chemistry ; Optoelectronics ; Physics ; Organic chemistry Multiferroics and related materials ; Ferroelectric and Piezoelectric Materials ; Magnetic Properties and Synthesis of Ferrites
Authors: Jan Eric Stehr | Mattias Jansson | S. J. Pearton | John S. McCloy | Jani Jesenovec | B. Dutton | Matthew D. McCluskey | Weimin Chen | I. A. Buyanova
Source: Applied Physics Letters (article, 2024-01-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Color center in <b> <i>β</i> </b>-Ga2O3 emitting at the telecom range Transition metal (TM) ions incorporated into a host from a wide bandgap semiconductor are recognized as a promising system for quantum technologies with enormous potential. In this work, we report on a TM color center in β-Ga2O3 with physical properties attractive for quantum information applications. The center is found to emit at 1.316 μm and exhibits weak coupling to phonons, with optically addressable higher-lying excited states, beneficial for single-photon emission within the telecom range (O-band). Using magneto-photoluminescence (PL) complemented by time-resolved PL measurements, we identify the monitored emission to be internal 1E→3A2 spin-forbidden transitions of a 3d8 TM ion with a spin-triplet ground state—a possible candidate for a spin qubit. We tentatively attribute this color center to a complex involving a sixfold coordinated Cu3+ ion. Excited state ; Photoluminescence ; Qubit ; Center (category theory) ; Atomic physics ; Spin (aerodynamics) ; Ion ; Physics ; Ground state ; Quantum dot ; Band gap ; Photon ; Phonon ; Range (aeronautics) ; Spin states ; Optoelectronics ; Quantum ; Materials science ; Condensed matter physics ; Chemistry ; Optics ; Quantum mechanics ; Crystallography Ga2O3 and related materials ; ZnO doping and properties ; Electronic and Structural Properties of Oxides
Authors: Y. Watanabe
Source: Journal of Applied Physics (article, 2024-06-14)
Field: Materials Science — Materials Chemistry

DFT + <i>U</i> accurate for strain effect and overall properties of perovskite oxide ferroelectrics and polaron We find that the unit cell volume (V), which affects many properties, decreases too rapidly with strain when calculated with standard density functional theories (DFTs) such as local density approximation (LDA). We find that this demerit is moderated with the use of the Hubbard potential U for local electron correlation (DFT + U). However, the introduction of U to standard DFTs, e.g., LDA and Perdew–Burke–Ernzerhof functional (PBE) optimized for solids (PBEsol), leads to the excessive underestimation of the spontaneous polarization (PS) and frequently extinguishes PS. Therefore, we attempt to improve the overall accuracy of DFTs for ferroelectrics by using U in several DFT methods including PBE that overestimates PS and lattice constants. We demonstrate that PBE with U (PBE + U) is in excellent agreement with the experimental properties of BaTiO3 and SrTiO3, with improvements in the estimates of lattice constants, PS, the phonon frequency, the antiferrodistortive angle of 105 K-phase SrTiO3, the bandgap, the strain dependence of V, and hole polarons. When the lattice parameters and PS moderately agree with the experimental data, PBE + U with a single U set can produce both electron and hole polarons. Hence, PBE + U can be a practical substitute of hybrid functionals for perovskite oxide ferroelectrics, except for the estimation of the bandgap. Furthermore, we propose an approach to construct a functional accurately depicting the incipient ferroelectric state of SrTiO3. Additionally, these results suggest that conventional DFT underestimates PS under compressive in-plane strain and predicts the unrealistic deformation of ferroelectrics and that in-plane-strained lattices can mitigate the problems associated with U. Polaron ; Density functional theory ; Materials science ; Lattice constant ; Condensed matter physics ; Band gap ; Perovskite (structure) ; Hybrid functional ; Ferroelectricity ; Lattice (music) ; Local-density approximation ; Electron ; Computational chemistry ; Crystallography ; Physics ; Chemistry ; Diffraction ; Quantum mechanics ; Optoelectronics ; Dielectric Electronic and Structural Properties of Oxides ; Ferroelectric and Piezoelectric Materials ; Magnetic and transport properties of perovskites and related materials
Authors: Shu‐Han Liao | Chih-Hsuan Wang | Pei-Xiu Ke | Cheng‐Fu Yang
Source: Photonics (article, 2024-02-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Using Planar Metamaterials to Design a Bidirectional Switching Functionality Absorber—An Ultra-Wideband Optical Absorber and Multi-Wavelength Resonant Absorber This study aimed to investigate a bidirectional switching functionality absorber, which exhibited an ultra-wideband characteristic in one direction, while in the other direction it demonstrated the absorption of three different resonant wavelengths (frequencies). The fully layered planar structure of the absorber consisted of Al2O3, Zr, yttria-stabilized zirconia (YSZ), Zr, YSZ, Al, YSZ, and Al. The simulations were conducted using the COMSOL Multiphysics® simulation software (version 6.1) for analyses, and this study introduced three pivotal innovations. Firstly, there had been scarce exploration of YSZ and Zr as the materials for designing absorbers. The uses of YSZ and Zr in this context were a relatively uncharted territory, and our research endeavored to showcase their distinctive performance as absorber materials. Secondly, the development of a planar absorber with multifunctional characteristics was a rarity in the existing literature. This encompassed the integrations of an ultra-wideband optical absorber and the creation of a multi-wavelength resonant absorber featuring three resonant wavelengths. The design of such a multi-wavelength resonant absorber holds promise for diverse applications in optical detection and communication systems, presenting novel possibilities in related fields. Lastly, a notable discovery was demonstrated: a discernible redshift phenomenon in the wavelengths of the three resonant peaks when the thickness of YSZ, serving as the material of resonant absorber layer, was increased. Planar ; Metamaterial absorber ; Metamaterial ; Wideband ; Materials science ; Optoelectronics ; Wavelength ; Optics ; Optical switch ; Tunable metamaterials ; Physics ; Computer science Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Antenna Design and Analysis
Authors: Yang Hu | Dennis M. Kochmann
Source: Materials Research Letters (article, 2024-10-28)
Field: Materials Science — Biomaterials

Unconventional {101¯2} twinning assisted by pyramidal II stacking faults Twinning significantly affects the deformation behavior of hexagonal close-packed Mg, so a thorough understanding of twin nucleation and growth mechanisms is required for enhancing the properties of Mg-based materials. The commonly observed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>{</mml:mo> <mml:mn>10</mml:mn> <mml:mrow><mml:mover><mml:mn>1</mml:mn> <mml:mo>¯</mml:mo></mml:mover> </mml:mrow> <mml:mn>2</mml:mn> <mml:mo>}</mml:mo></mml:mrow> </mml:math> tension twins have been traditionally linked to 〈c + a〉 dislocation dissociation, which results in zonal dislocations with large Burgers vectors several times that of a single twinning dislocation and some residual dislocations. Contrarily, our molecular dynamics simulations reveal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>{</mml:mo> <mml:mn>10</mml:mn> <mml:mrow><mml:mover><mml:mn>1</mml:mn> <mml:mo>¯</mml:mo></mml:mover> </mml:mrow> <mml:mn>2</mml:mn> <mml:mo>}</mml:mo></mml:mrow> </mml:math> twin nucleation from pyramidal II stacking faults through atomic shuffling without shear displacements. This introduces an alternative twin nucleation mechanism, different from the classically accepted mechanism of dislocation dissociation. Crystal twinning ; Materials science ; Stacking ; Crystallography ; Composite material ; Microstructure ; Physics ; Nuclear magnetic resonance ; Chemistry Magnesium Alloys: Properties and Applications ; Microstructure and mechanical properties