jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zamzuri Zamzuri | N Nisha Razalli | M Mahyiddin | M. Marina | H. Jaafar
Source: Journal of Advanced Research in Applied Sciences and Engineering Technology (article, 2024-12-24)
Field: Materials Science — Materials Chemistry

Insight into Magnesium Doping on Morphology, Optical and Electrical Properties of Cu2O Layer synthesized by Electrodeposition Method Cu2O stands out as a promising semiconductor material for solar energy conversion, primarily due to its exceptional light-absorbing qualities and its widespread availability. However, its efficiency is somewhat hindered by its relatively low carrier mobility and a limited absorption band for carriers. The introduction of magnesium (Mg) doping into Cu2O has emerged as a potential means to enhance its morphology, optical characteristics, and electrical properties, making it an intriguing avenue for exploration. To fabricate the Mg-doped Cu2O layers, an electrodeposition process was employed on an Indium Tin Oxide (ITO) substrate. The resulting films were then subjected to characterization using Field Emission Scanning Electron Microscopy (FESEM), Ultraviolet-Visible Spectroscopy (UV-Vis), and HALL Effect Measurement, focusing on their morphology, optical properties, and electrical behaviors. Notably, the concentration of magnesium played a significant role in shaping the properties of the Cu2O layer. The fabrication process extended up to a dopant concentration of 0.3 M for both undoped Cu2O and Mg-doped Cu2O layers, leading to morphological alterations. Specifically, the grain size increased with varying dopant concentrations, but it became smaller and more compact after doping with 0.3 M Mg. The average absorbance of visible light for both undoped and Mg-doped Cu2O layers fell within the range of 1~2 au. Intriguingly, a doping level of 0.3 M Mg led to the simultaneous achievement of high carrier mobility (29.98 cm2/Vs), low bulk carrier concentration (2.3.928 x 1021 cm-3), and high resistivity (5.3 x 10-5 Ωcm) in the Cu2O material. Additionally, Cu2O/ITO thin films exhibiting rectifying characteristics were successfully fabricated, confirming the semiconductor nature of the deposited p-type Cu2O layer. The primary objective of this study was to synthesize Cu2O layers doped with varying concentrations of Mg and thoroughly characterize their morphology, optical attributes, and electrical behaviors through the electrodeposition method. The study findings and implications were extensively discussed. Magnesium ; Doping ; Morphology (biology) ; Layer (electronics) ; Materials science ; Nanotechnology ; Optoelectronics ; Chemical engineering ; Metallurgy ; Engineering ; Geology Copper-based nanomaterials and applications ; ZnO doping and properties ; Electronic and Structural Properties of Oxides
Authors: Victor Ukleev | Oleg I. Utesov | Chen Luo | F. Radu | Sebastian Wintz | Markus Weigand | Simone Finizio | Moritz Winter | Alexander Tahn | Bernd Rellinghaus | Kosuke Karube | Yoshinori Tokura | Yasujiro Taguchi | J. S. White
Source: arXiv (Cornell University) (preprint, 2024-04-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Competing anisotropies in the chiral cubic magnet Co$_8$Zn$_8$Mn$_4$ unveiled by resonant x-ray magnetic scattering The cubic $β$-Mn-type alloy Co$_8$Zn$_8$Mn$_4$ is a chiral helimagnet that exhibits a peculiar temperature-dependent behavior in the spiral pitch, which decreases from 130 nm at room temperature to 70 nm below 20 K. Notably, this shortening is also accompanied by a structural transition of the metastable skyrmion texture, transforming from a hexagonal lattice to a square lattice of elongated skyrmions. The underlying mechanism of these transformations remain unknown, with interactions potentially involved including temperature-dependent Dzyaloshinskii-Moriya interaction, magnetocrystalline anisotropy, and exchange anisotropy. Here, x-ray resonant magnetic small-angle scattering in vectorial magnetic fields was employed to investigate the temperature dependence of the anisotropic properties of the helical phase in Co$_8$Zn$_8$Mn$_4$. Our results reveal quantitatively that the magnitude of the anisotropic exchange interaction increases by a factor of 4 on cooling from room temperature to 20 K, leading to a 5% variation in the helical pitch within the (001) plane at 20 K. While anisotropic exchange interaction contributes to the shortening of the spiral pitch, its magnitude is insufficient to explain the variation in the spiral periodicity from room to low temperatures. Finally, we demonstrate that magnetocrystalline and exchange anisotropies compete, favoring different orientations of the helical vector in the ground state. Magnet ; Scattering ; Anisotropy ; X-ray ; Condensed matter physics ; Materials science ; Physics ; Optics ; Quantum mechanics Magnetic Properties of Alloys ; Magnetic properties of thin films ; Magnetic Properties and Applications
Authors: Mohammed M. Kummali | David R. Cole | Siddharth Gautam
Source: arXiv (Cornell University) (preprint, 2024-02-06)
Field: Chemistry — Inorganic Chemistry

Mixtures of Ethane with CO$_2$ and Water Simulated in ZSM-22: The Role of Polarity and Hydrogen Bonding Deciphering the interplay between confinement effects and intermolecular interactions in zeolites is crucial for understanding diverse diffusion behaviors of confined molecules. Recent studies explored the impact of water and CO$_2$ on hydrocarbon dynamics in nanoporous materials. However, differing nanoporous materials, as used in these studies complicate the comparative analysis of CO$_2$ and water effects on hydrocarbons, necessitating a comprehensive investigation with identical confining media and consistent pore diameters. In this study, we investigate the diffusion of ethane, CO$_2$, and water in ZSM-22 molecular sieves. Additionally, we examine the effect of hydration and CO$_2$ on ethane diffusion through the study of ethane-water and ethane-CO$_2$ mixtures. Results indicate enhanced translational motions of CO$_2$ in mixtures, while CO$_2$ minimally affects ethane diffusion. In contrast, water is found to slow down the diffusion of ethane by making molecular bridges across the pores. Ethane hampers the translational dynamics of water molecules. Hydrogen bonding in water and the molecular polarity of the fluids are found to play an important role in determining the effects of the presence of one species on the motion of the other. Rotation of the fluid molecules in ZSM-22 is found to occur at two-time scales in both pure state as well as in fluid mixtures. While the short-time fast rotation is determined by the moment of inertia, the long-time rotation is affected by the interaction between fluid molecules and the zeolite atoms. In the case of water, hydrogen bonding hinders rotation and inhibits complete rotation. Polarity (international relations) ; ZSM-5 ; Hydrogen ; Hydrogen bond ; Chemistry ; Photochemistry ; Materials science ; Catalysis ; Organic chemistry ; Zeolite ; Molecule Zeolite Catalysis and Synthesis ; Phase Equilibria and Thermodynamics ; Carbon Dioxide Capture Technologies
Authors: Didrik R. Småbråten | Frida Hemstad Danmo | Nikolai Helth Gaukås | Sathya Prakash Singh | Nikola Kanas | Dennis Meier | Kjell Wiik | Mari‐Ann Einarsrud | Sverre M. Selbach
Source: arXiv (Cornell University) (preprint, 2024-11-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Controlling electronic properties of hexagonal manganites through aliovalent doping and thermoatmospheric history The family of hexagonal manganites is intensively studied for its multiferroicity, magnetoelectric coupling, improper ferroelectricity, functional domain walls, and topology-related scaling behaviors. It is established that these physical properties are co-determined by the cation sublattices and that aliovalent doping can readily be leveraged to modify them. The doping, however, also impacts the anion defect chemistry and semiconducting properties, which makes the system highly sensitive to the synthesis and processing conditions. Here, we study the electronic properties of YMnO3 as function of aliovalent cation doping and thermoatmospheric history, combining density functional theory calculations with thermopower and thermogravimetric measurements. We show that the charge carrier concentration and transport properties can be controlled via both aliovalent cation dopants and anion defects, enabling reversible switching between n-type and p-type conductivity. This tunability is of importance for envisaged applications of hexagonal manganites in, e.g. next-generation capacitors and domain-wall nanoelectronics, or as catalysts or electrodes in fuel cells or electrolyzers. Furthermore, our approach is transferrable to other transition metal oxides, providing general guidelines for controlling their semiconducting properties. Doping ; Hexagonal crystal system ; Materials science ; Condensed matter physics ; Optoelectronics ; Crystallography ; Chemistry ; Physics Magnetic and transport properties of perovskites and related materials ; Electronic and Structural Properties of Oxides ; Gas Sensing Nanomaterials and Sensors
Authors: Sowmya Kanakamedala
Source: International Journal for Research in Applied Science and Engineering Technology (article, 2024-06-11)
Field: Materials Science — Materials Chemistry

Investigation of the Structural, Electrical, and Optical Properties of Co-Precipitation-Synthesized Aluminum-Doped ZnO Nanostructures Abstract: This study examines the Structural, Electrical, and Optical characteristics of Zinc Oxide substituted with aluminum (AlxZn1-xO; x = 0, 0.02, 0.04, 0.06, 0.08). The coprecipitation technique is used to synthesize the powders, and X-ray diffraction (XRD) is used to analyze the powders' structural properties. Field Emission Scanning Electron Microscopy (FESEM) is used to study the morphological characteristics of the produced powders. The UV-visible absorbance spectrum (UV-Vis.) was used to assess the particles' optical characteristics. Using photoluminescence (PL) spectra, the effects of morphology on the optical and electrical characteristics of produced powders were examined. The XRD patterns verified that a single-phase hexagonal wurtzite structure formed for each sample. The powders' FESEM pictures reveal how, as the Al concentration increases, the particles' morphology alters from hexagonal to spherical. The synthesized samples have crystallite sizes between 19 and 26 nm. The predictable variations noticed with Al3+ concentration are consistent with Al3+ incorporation into the ZnO lattice, as confirmed by the UV-Vis spectroscopy measurements. Materials science ; Nanostructure ; Doping ; Precipitation ; Aluminium ; Chemical engineering ; Nanotechnology ; Metallurgy ; Optoelectronics ; Physics ZnO doping and properties
Authors: Nishal M. Egodawaththa | Olivia Rajhel | Jingxuan Ma | Charitha Guruge | Alec B. Pabarue | E. J. Harris | Roberto Peverati | Nasri Nesnas
Source: Organic & Biomolecular Chemistry (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Highly efficient Ca<sup>2+</sup> chelation activated by visible light Calcium ion (Ca<sup>2+</sup>) control is an essential tool in neuronal research. Herein, we report three thiocoumarin-based, visible light-activated Ca<sup>2+</sup> chelators with quantum yields of 0.39, 0.52, and 0.83. The chelators demonstrated an over 10<sup>5</sup>-fold increase in Ca<sup>2+</sup> binding affinity upon irradiation. These chelators are efficiently triggered by biologically safer wavelengths, rendering them excellent candidates for use in neurological research and medicine. Chelation ; Calcium ; Chemistry ; Radiochemistry ; Ion ; Nuclear chemistry ; Inorganic chemistry Photochromic and Fluorescence Chemistry ; Photoreceptor and optogenetics research ; Radical Photochemical Reactions
Authors: A. Rambabu | Mounika Gandi | K. Jayadev | B. Sridhar
Source: East European Journal of Physics (article, 2024-12-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Structural, Dielectric and Magnetic Properties of Epitaxial Grown YMn0.5Cr0.5O3 thin films YCr(1-x)MnxO3 is an intriguing member of the perovskite family, attracting significant interest due to its versatile properties and potential applications in various fields. Epitaxial orthorhombic YMn0.5Cr0.5O3 films are grown on STO substrates by pulsed laser deposition method. Well crystalline with (0 ℓ 0) orientation of YMn0.5Cr0.5O3 films are identified by X-ray diffraction. Field emission scanning electron microscopy used to capture the morphological behavior of crystalline YMn0.5Cr0.5O3 films. Temperature-dependent dielectric properties are analyzed thoroughly. The magnetic properties of YMn0.5Cr0.5O3 films are characterized using physical property measurement system. There is a clear magnetic transition observed around 60K for three YMn0.5Cr0.5O3 films. Films deposited at 600oC exhibited high dielectric and magnetic properties. Materials science ; Dielectric ; Epitaxy ; Thin film ; Condensed matter physics ; Composite material ; Optoelectronics ; Nanotechnology ; Physics Multiferroics and related materials ; Magnetic and transport properties of perovskites and related materials ; Electrical and Thermal Properties of Materials
Authors: Charlie Nation | Valentina Notararigo | Hallmann Óskar Gestsson | Luca Sapienza | Alexandra Olaya-Castro
Source: arXiv (Cornell University) (preprint, 2024-02-29)
Field: Chemistry — Electrochemistry

Two-colour photon correlations probe coherent vibronic contributions to electronic excitation transport under incoherent illumination Identifying signatures of quantum coherent behaviour in photoactive systems that are maintained in stationary states away from thermal equilibrium is an open problem of wide interest in a variety of physical scenarios, including single photosynthetic complexes subjected to continuous incoherent illumination. Here we consider a prototype light-harvesting heterodimer exhibiting coherent and collective exciton-vibration interactions and show that the second-order frequency-filtered correlations of fluorescence photons provide insightful information on the influence of such coherent interactions for different transitions, thereby yielding fundamentally different photon-counting statistics. Furthermore, we show that coherent vibronic mechanisms strongly affect the asymmetries characteristic of time-resolved photon cross-correlations and manifest themselves in a time-dependent violation of the Cauchy-Schwarz inequality bounding cross-correlations for classically fluctuating fields. We finally discuss how such second-order correlation asymmetry establishes important connections between coherent vibronic interactions, directional exciton population transport, and violation of quantum detailed balance. Our work then indicates that measurement of two-colour photon correlation asymmetry can be an important avenue to investigate quantum behaviour of single photoactive biomolecular and chemical systems under incoherent illumination conditions. Excitation ; Two-photon excitation microscopy ; Vibronic spectroscopy ; Photon ; Physics ; Atomic physics ; Vibronic coupling ; Molecular physics ; Materials science ; Optics ; Quantum mechanics ; Excited state Electrochemical Analysis and Applications ; Spectroscopy and Quantum Chemical Studies ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: Wen‐Shan Zhang | Nikolai Hippchen | Rasmus R. Schröder | Uwe H. F. Bunz
Source: BIO Web of Conferences (article, 2024-01-01)
Field: Materials Science — Surfaces, Coatings and Films

In-Situ Charging and Charging Map for Characterization of Electronic Materials ConclusionBy employing in-situ charging and charging maps via ULV-SEM, we gather information regarding various morphological phenomena.This enables us to directly correlate device performance with the chemical structure of the active material and its morphology, thereby facilitating the design of novel structures and the optimization of the active layer in electronic devices. In situ ; Characterization (materials science) ; Materials science ; Nanotechnology ; Physics ; Meteorology Electron and X-Ray Spectroscopy Techniques ; Advancements in Photolithography Techniques ; Integrated Circuits and Semiconductor Failure Analysis
Authors: Seena Elizabeth George
Source: International Journal of Science and Research (IJSR) (article, 2024-09-05)
Field: Chemistry — Organic Chemistry

Exploring Thiophene Compounds: Pioneering Applications in Organic Electronics This review explores the pivotal role of thiophene compounds in the rapidly advancing field of organic electronics. Due to their unique electronic properties, chemical versatility and structural stability, thiophene derivatives have become essential materials in various applications like organic solar cells (OSCs), organic light emitting diodes (OLEDs) and Organic field effect transistors (OFETs). The review high lights recent progress in the design, synthesis and applications of thiophene based compounds. Thiophene ; Organic electronics ; Electronics ; Nanotechnology ; Materials science ; Engineering physics ; Chemistry ; Engineering ; Organic chemistry ; Electrical engineering ; Transistor Organic Chemistry Cycloaddition Reactions
Authors: Saleh Ahmed Khan | Ahmed Ibreljic | Stephen Margiotta | A F M Anhar Uddin Bhuiyan
Source: arXiv (Cornell University) (preprint, 2024-11-29)
Field: Materials Science — Electronic, Optical and Magnetic Materials

LPCVD Grown Si-Doped $β$-Ga$_2$O$_3$ Films with Promising Electron Mobilities We systematically investigated the growth of Si-doped $β$-Ga$_2$O$_3$ films using LPCVD system, achieving high electron mobilities of 162 cm$^2$/V.s and 149 cm$^2$/V.s at carrier concentrations of $1.51 \times 10^{17}$ cm$^{-3}$ and $1.15 \times 10^{17}$ cm$^{-3}$, respectively, for homoepitaxial (010) $β$-Ga$_2$O$_3$ films grown on $β$-Ga$_2$O$_3$ substrates and heteroepitaxial (-201) $β$-Ga$_2$O$_3$ films grown on off-axis c-sapphire substrates with 6° miscut, representing the highest mobilities reported for LPCVD-grown $β$-Ga$_2$O$_3$ materials. Carrier concentrations were precisely tuned by varying SiCl$_4$ flow rates at a growth temperature of 1000°C, resulting in concentrations ranging from $1.15 \times 10^{17}$ to $1.19 \times 10^{19}$ cm$^{-3}$, as confirmed by both Hall and C-V measurements. The films exhibited high crystalline quality, confirmed by high-resolution XRD and Raman spectroscopy, indicating phase purity and structural integrity. Surface morphologies characterized by FESEM and AFM imaging showed a strong correlation between carrier concentrations and surface smoothness, with lower concentrations resulting in reduced RMS roughness. SIMS analysis revealed uniform Si incorporation, with low carbon, hydrogen, and chlorine impurities below detection limits, indicating high purity of the films. A high low-temperature peak mobility exceeding 843 cm$^2$/V$\cdot$s was achieved for (-201) $β$-Ga$_2$O$_3$ films at 80 K, highlighting the high purity and low compensation of these films. These findings emphasize the potential of LPCVD growth system for producing high-purity $β$-Ga$_2$O$_3$ films with thickness ranging between ~2.3-11.7 $μ$m and faster growth rates (~4.7-17 $μ$m/hr), promising transport properties, controllable doping, and scalability for developing high power vertical devices. Doping ; Mobilities ; Materials science ; Chemical vapor deposition ; Optoelectronics ; BETA (programming language) ; Electron ; Nanotechnology ; Computer science ; Physics ; Sociology Ga2O3 and related materials ; Semiconductor materials and devices ; Electronic and Structural Properties of Oxides
Authors: 王颖 Wang Ying | 李春树 Li Chunshu | 闫翔 Yan Xiang
Source: Laser & Optoelectronics Progress (article, 2024-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

太赫兹波段方向图可重构微带阵列天线设计 结合石墨烯材料在太赫兹波段下具有利于阻抗匹配、电可控的独特优势与可重构微带阵列天线高辐射效率等特点，设计了一款适用于太赫兹波段基于石墨烯材料的方向图可重构微带阵列天线。该阵列天线的天线单元在辐射贴片中嵌入石墨烯贴片充当开关，通过调节石墨烯的外加偏置电压改变开关的导通与截止状态。天线单元及阵列天线的工作频率皆为5.012 THz，天线单元在工作频率可以实现12°~24°的方向图调整，且具有良好的增益特性及抗干扰性，由天线单元组成的2×2的微带阵列天线可实现在0°~13°的方向图可重构功能，仿真结果表明，阵列天线的最大增益为12.5 dBi，最大波束宽度为51.4°，具有较好的方向性与抗干扰能力。 Computer science Metamaterials and Metasurfaces Applications ; Plasmonic and Surface Plasmon Research
Authors: Jianyu Li | Ji Liu | Mingjun Han | Waqas Haider | Yusuke Nomura | Ho-Kin Tang
Source: arXiv (Cornell University) (preprint, 2024-09-02)
Field: Materials Science — Materials Chemistry

Variation of Electron-electron interaction in pyrochlore structures We conduct a comprehensive \textit{ab initio} investigation of electron-electron interactions within the pyrochlore structures of R$_2$Ru$_2$O$_7$, R$_2$Ir$_2$O$_7$, Ca$_2$Ru$_2$O$_7$, and Cd$_2$Ru$_2$O$_7$, where R denotes a rare-earth element. Utilizing a multiorbital Hubbard model, we systematically explore the effects of various rare-earth elements and applied high pressure on the correlation strength in these compounds. Our calculations on the Coulomb interaction parameter $U$ and the bandwidth $W$ reveal that the chemical pressure for R$_2$Ru$_2$O$_7$ and R$_2$Ir$_2$O$_7$ leads to an unusual increase in $U/W$ ratio, hence, increase in correlation strength. Contrary to conventional understanding of bandwidth control, our study identifies that the Hubbard $U$ is more influential than the bandwidth $W$ behind the metal-insulator landscape of R$_2$Ru$_2$O$_7$ and R$_2$Ir$_2$O$_7$, leading to an interaction-controlled metal-insulator transition. We also find unexpected behavior in physical pressure. Whereas physical pressure leads to a decrease in the correlation strength $U/W$ as usual in R$_2$Ru$_2$O$_7$, the effect is notably small in Ca$_2$Ru$_2$O$_7$ and Cd$_2$Ru$_2$O$_7$, which provides an important clue to understanding unusual pressure-induced metal-insulator transition observed experimentally. Pyrochlore ; Electron ; Variation (astronomy) ; Physics ; Astrophysics ; Nuclear physics ; Quantum mechanics Nuclear materials and radiation effects
Authors: K. Jyothi | M. Kannadasan
Source: Asian Journal of Chemistry (article, 2024-11-30)
Field: Chemistry — Organic Chemistry

Novel Pyrimidine Tethered Benzamide Derivatives as Potential Anticancer Agents: Synthesis, Characterization, Molecular Docking and In vitro Cytotoxicity Evaluation Current research work presents the synthesis, characterization, molecular docking study and in vitro cytotoxicity evaluation of novel pyrimidine-tethered benzamide derivatives as potential anticancer agents. The synthesis involved multi-steps procedure, including the synthesis of various chalcones (3a-t) with corresponding ketones (1 and 2) and substituted aldehydes (a-j), followed by pyrimidine amines (5a-t) with condensation of chalcones and guanidine and finally pyrimidinyl benzamide derivatives (8a-t) from compounds 5a-t coupling with acid chloride (7) using DIBAL-H. Synthesized compounds characterized by NMR spectroscopy and HRMS. The molecular docking studies were conducted against EGFR (6LUD) and CDK-4 (7SJ3) receptors, revealing distinct binding affinities influenced by substituent groups. Additionally, the cytotoxicity of the synthesized compounds was evaluated using the MTT assay against various cancer cell lines, including A-549 (non-small cell lung cancer), HCT-116 (colorectal cancer), PANC-1 (pancreatic cancer) and HaLa (cervical cancer), along with one normal human embryonic kidney cell line (HEK-293). Among the synthesized compounds, derivatives 8f and 8j exhibited the best anticancer activity against A-549 cells, compounds 8j and 8e showed exceptional potency against HCT-116 cells, compounds 8f and 8j demonstrated high efficacy against PANC-1 cells and compound 8h displayed remarkable potency against HaLa cells. The findings highlight the potential of these pyrimidinyl benzamide derivatives as targeted anticancer agents. Chemistry ; Benzamide ; Cytotoxicity ; Pyrimidine ; In vitro ; Docking (animal) ; Stereochemistry ; Combinatorial chemistry ; Pharmacology ; Biochemistry Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Synthesis of Tetrazole Derivatives