Subjects -> PHYSICS (Total: 857 journals)
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    - PHYSICS (625 journals)
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PHYSICS (625 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 741 Journals sorted alphabetically
Acta Acustica     Open Access   (Followers: 4)
Acta Mechanica     Hybrid Journal   (Followers: 22)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
Advanced Composite Materials     Hybrid Journal   (Followers: 75)
Advanced Electronic Materials     Hybrid Journal   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 72)
Advanced Materials     Hybrid Journal   (Followers: 259)
Advanced Quantum Technologies     Hybrid Journal   (Followers: 3)
Advanced Science Focus     Free   (Followers: 6)
Advanced Structural and Chemical Imaging     Open Access   (Followers: 2)
Advanced Studies in Theoretical Physics     Open Access   (Followers: 5)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 2)
Advances in Clinical Radiology     Full-text available via subscription   (Followers: 4)
Advances in Condensed Matter Physics     Open Access   (Followers: 5)
Advances in Geophysics     Full-text available via subscription   (Followers: 7)
Advances in High Energy Physics     Open Access   (Followers: 23)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 4)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 33)
Advances in Natural Sciences : Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in OptoElectronics     Open Access   (Followers: 7)
Advances In Physics     Hybrid Journal   (Followers: 29)
Advances in Physics : X     Open Access   (Followers: 4)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Remote Sensing     Open Access   (Followers: 59)
Aggregate     Open Access   (Followers: 2)
AIP Advances     Open Access   (Followers: 7)
AIP Conference Proceedings     Full-text available via subscription   (Followers: 2)
American Journal of Condensed Matter Physics     Open Access   (Followers: 7)
American Journal of Signal Processing     Open Access   (Followers: 14)
Anales (Asociación Física Argentina)     Open Access  
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 9)
Annalen der Physik     Hybrid Journal   (Followers: 5)
Annales Geophysicae (ANGEO)     Open Access   (Followers: 21)
Annales Henri Poincaré     Hybrid Journal   (Followers: 2)
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 6)
Annals of Physics     Hybrid Journal   (Followers: 7)
Annals of West University of Timisoara - Physics     Open Access   (Followers: 1)
Annual Reports on NMR Spectroscopy     Full-text available via subscription   (Followers: 4)
Annual Review of Analytical Chemistry     Full-text available via subscription   (Followers: 12)
Annual Review of Condensed Matter Physics     Full-text available via subscription   (Followers: 3)
Annual Review of Materials Research     Full-text available via subscription   (Followers: 8)
APL Materials     Open Access   (Followers: 12)
Applied Composite Materials     Hybrid Journal   (Followers: 54)
Applied Mathematics and Physics     Open Access   (Followers: 2)
Applied Physics A     Hybrid Journal   (Followers: 15)
Applied Physics Frontier     Open Access   (Followers: 2)
Applied Physics Letters     Hybrid Journal   (Followers: 45)
Applied Physics Research     Open Access   (Followers: 5)
Applied Physics Reviews     Hybrid Journal   (Followers: 11)
Applied Radiation and Isotopes     Hybrid Journal   (Followers: 4)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Spectroscopy Reviews     Hybrid Journal   (Followers: 4)
Archive for Rational Mechanics and Analysis     Hybrid Journal   (Followers: 2)
Asia Pacific Physics Newsletter     Hybrid Journal   (Followers: 1)
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 2)
ASTRA Proceedings     Open Access   (Followers: 3)
Astronomy & Geophysics     Hybrid Journal   (Followers: 50)
Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 39)
Atoms     Open Access   (Followers: 1)
Attention, Perception & Psychophysics     Full-text available via subscription   (Followers: 15)
Axioms     Open Access   (Followers: 1)
Bangladesh Journal of Medical Physics     Open Access  
Bauphysik     Hybrid Journal   (Followers: 1)
Biomaterials     Hybrid Journal   (Followers: 55)
Biomedical Imaging and Intervention Journal     Open Access   (Followers: 5)
Biophysical Reviews     Hybrid Journal   (Followers: 2)
Biophysical Reviews and Letters     Hybrid Journal   (Followers: 5)
BJR|Open     Open Access  
Boson Journal of Modern Physics     Open Access   (Followers: 9)
Brazilian Journal of Physics     Hybrid Journal  
Bulletin of Materials Science     Open Access   (Followers: 44)
Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics     Open Access  
Bulletin of the Atomic Scientists     Hybrid Journal   (Followers: 7)
Bulletin of the Lebedev Physics Institute     Hybrid Journal  
Bulletin of the Russian Academy of Sciences: Physics     Hybrid Journal   (Followers: 1)
Caderno Brasileiro de Ensino de Física     Open Access  
Canadian Journal of Physics     Hybrid Journal   (Followers: 11)
Cell Reports Physical Science     Open Access  
Cells     Open Access   (Followers: 2)
CERN courier. International journal of high energy physics     Free   (Followers: 8)
Chemical Physics Impact     Full-text available via subscription  
ChemPhysMater     Full-text available via subscription  
Chinese Journal of Chemical Physics     Hybrid Journal   (Followers: 1)
Chinese Journal of Physics     Hybrid Journal   (Followers: 1)
Ciencia     Open Access  
Clinical Spectroscopy     Open Access   (Followers: 1)
Cogent Physics     Open Access  
Colloid Journal     Hybrid Journal   (Followers: 3)
Communications in Mathematical Physics     Hybrid Journal   (Followers: 2)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Communications Materials     Open Access  
Communications Physics     Open Access  
Complex Analysis and its Synergies     Open Access   (Followers: 2)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 185)
Composites Part B : Engineering     Hybrid Journal   (Followers: 227)
Composites Part C : Open Access     Open Access   (Followers: 2)
Computational Astrophysics and Cosmology     Open Access   (Followers: 7)
Computational Condensed Matter     Open Access   (Followers: 1)
Computational Materials Science     Hybrid Journal   (Followers: 26)
Computational Mathematics and Mathematical Physics     Hybrid Journal   (Followers: 5)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computer Physics Communications     Hybrid Journal   (Followers: 9)
Condensed Matter     Open Access   (Followers: 2)
Contemporary Physics     Hybrid Journal   (Followers: 26)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 8)
Contributions to Plasma Physics     Hybrid Journal   (Followers: 3)
Cryogenics     Hybrid Journal   (Followers: 62)
Current Applied Physics     Full-text available via subscription   (Followers: 4)
Current Science     Open Access   (Followers: 118)
Diagnostic and Interventional Imaging     Full-text available via subscription  
Diamond and Related Materials     Hybrid Journal   (Followers: 10)
Discrete and Continuous Models and Applied Computational Science     Open Access  
Doklady Physics     Hybrid Journal   (Followers: 1)
e-Boletim da Física     Open Access  
East European Journal of Physics     Open Access   (Followers: 1)
Edufisika : Jurnal Pendidikan Fisika     Open Access  
EDUSAINS     Open Access  
Egyptian Journal of Remote Sensing and Space Science     Open Access   (Followers: 26)
EJNMMI Physics     Open Access  
Emergent Scientist     Open Access  
Engineering Failure Analysis     Hybrid Journal   (Followers: 68)
Engineering Fracture Mechanics     Hybrid Journal   (Followers: 24)
Environmental Fluid Mechanics     Hybrid Journal   (Followers: 11)
EPJ Quantum Technology     Open Access   (Followers: 2)
EPJ Techniques and Instrumentation     Open Access  
EPJ Web of Conferences     Open Access   (Followers: 1)
EUREKA : Physics and Engineering     Open Access  
European Physical Journal - Applied Physics     Full-text available via subscription   (Followers: 19)
European Physical Journal C     Hybrid Journal   (Followers: 2)
Europhysics News     Open Access  
Experimental and Computational Multiphase Flow     Hybrid Journal  
Experimental Mechanics     Hybrid Journal   (Followers: 21)
Experimental Techniques     Hybrid Journal   (Followers: 51)
Exploration Geophysics     Hybrid Journal   (Followers: 4)
Few-Body Systems     Hybrid Journal   (Followers: 2)
Fire and Materials     Hybrid Journal   (Followers: 5)
FirePhysChem     Open Access  
Flexible Services and Manufacturing Journal     Hybrid Journal   (Followers: 2)
Fluctuation and Noise Letters     Hybrid Journal  
Fluid Dynamics     Hybrid Journal   (Followers: 27)
Fortschritte der Physik/Progress of Physics     Hybrid Journal  
Frontiers in Nanotechnology     Open Access   (Followers: 1)
Frontiers in Physics     Open Access   (Followers: 6)
Frontiers of Materials Science     Hybrid Journal   (Followers: 6)
Frontiers of Physics     Hybrid Journal   (Followers: 2)
Fusion Engineering and Design     Hybrid Journal   (Followers: 6)
Geochemistry, Geophysics, Geosystems     Full-text available via subscription   (Followers: 35)
Geografiska Annaler, Series A : Physical Geography     Hybrid Journal   (Followers: 4)
Geophysical Research Letters     Full-text available via subscription   (Followers: 167)
Giant     Open Access   (Followers: 1)
Glass Physics and Chemistry     Hybrid Journal  
Granular Matter     Hybrid Journal  
Graphs and Combinatorics     Hybrid Journal   (Followers: 4)
Gravitation and Cosmology     Hybrid Journal   (Followers: 7)
Heat Transfer - Asian Research     Hybrid Journal   (Followers: 11)
High Energy Density Physics     Hybrid Journal   (Followers: 3)
High Pressure Research: An International Journal     Hybrid Journal   (Followers: 3)
Himalayan Physics     Open Access   (Followers: 6)
IEEE Embedded Systems Letters     Hybrid Journal   (Followers: 60)
IEEE Journal of Quantum Electronics     Hybrid Journal   (Followers: 19)
IEEE Journal on Multiscale and Multiphysics Computational Techniques     Hybrid Journal  
IEEE Magnetics Letters     Hybrid Journal   (Followers: 7)
IEEE Nanotechnology Magazine     Hybrid Journal   (Followers: 45)
IEEE Reviews in Biomedical Engineering     Hybrid Journal   (Followers: 19)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 98)
IEEE Solid-State Circuits Magazine     Hybrid Journal   (Followers: 11)
IEEE Transactions on Autonomous Mental Development     Hybrid Journal   (Followers: 8)
IEEE Transactions on Biomedical Engineering     Hybrid Journal   (Followers: 35)
IEEE Transactions on Broadcasting     Hybrid Journal   (Followers: 11)
IEEE Transactions on Geoscience and Remote Sensing     Hybrid Journal   (Followers: 178)
IEEE Transactions on Haptics     Hybrid Journal   (Followers: 4)
IEEE Transactions on Industrial Electronics     Hybrid Journal   (Followers: 85)
IEEE Transactions on Industry Applications     Hybrid Journal   (Followers: 57)
IEEE Transactions on Learning Technologies     Full-text available via subscription   (Followers: 12)
IEEE Transactions on Quantum Engineering     Open Access   (Followers: 3)
IEEE Transactions on Services Computing     Hybrid Journal   (Followers: 5)
IEEE Transactions on Software Engineering     Hybrid Journal   (Followers: 84)
IEEE Women in Engineering Magazine     Hybrid Journal   (Followers: 12)
IEEE/OSA Journal of Optical Communications and Networking     Hybrid Journal   (Followers: 19)
IET Optoelectronics     Open Access   (Followers: 3)
Il Colle di Galileo     Open Access  
Image Analysis & Stereology     Open Access   (Followers: 1)
Imaging Science Journal     Hybrid Journal   (Followers: 3)
ImmunoInformatics     Open Access   (Followers: 1)
Indian Journal of Biochemistry and Biophysics (IJBB)     Open Access   (Followers: 3)
Indian Journal of Physics     Hybrid Journal   (Followers: 18)
Indian Journal of Pure & Applied Physics (IJPAP)     Open Access   (Followers: 36)
Indian Journal of Radio & Space Physics (IJRSP)     Open Access   (Followers: 49)
Infinite Dimensional Analysis, Quantum Probability and Related Topics     Hybrid Journal   (Followers: 1)
InfraMatics     Open Access  
Infrared Physics & Technology     Hybrid Journal   (Followers: 11)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 12)
Intermetallics     Hybrid Journal   (Followers: 21)
International Applied Mechanics     Hybrid Journal   (Followers: 5)
International Heat Treatment and Surface Engineering     Hybrid Journal   (Followers: 5)
International Journal for Computational Methods in Engineering Science and Mechanics     Hybrid Journal   (Followers: 13)
International Journal for Ion Mobility Spectrometry     Hybrid Journal   (Followers: 1)
International Journal for Simulation and Multidisciplinary Design Optimization     Open Access   (Followers: 5)
International Journal of Abrasive Technology     Hybrid Journal   (Followers: 2)
International Journal of Aeroacoustics     Hybrid Journal   (Followers: 38)

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Journal Cover
Advances in Condensed Matter Physics
Journal Prestige (SJR): 0.315
Citation Impact (citeScore): 1
Number of Followers: 5  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1687-8108 - ISSN (Online) 1687-8124
Published by Hindawi Homepage  [339 journals]
  • First-Principles Calculations to Investigate Structural, Electronic,
           Optical, and Elastic Properties of Ceria

    • Abstract: The structural, electronic, optical, and elastic properties of Ceria (CeO2) were investigated using local density approximation (LDA), PBE, DFT + U, and PBE0 approximations. In all approximations, the convergence test of total energy with respect to kinetic energy cutoff, k-point, and lattice constant of CeO2 was performed consequently to increase the accuracy of computations. The O (2p)-Ce (4f) bandgap of CeO2 calculated using DFT + U (3.0 eV) is consistent with experimentally reported value (3.0–3.33 eV) than with LDA (2.2 eV), PBE (2.5 eV), and PBE0 (4.47 eV). Both LDA and PBE underestimated the bandgap of CeO2 while the PBE0 overestimated the bandgap of CeO2 as compared to the experimental value. The optical properties such as the imaginary part of the dielectric function (), extinction coefficient (k), and refractive index (n) of ceria obtained using the three approaches are also consistent with the available theoretical and experimental data. In addition, the maximum peak for absorption coefficient was found at about 13 eV for (LDA and PBE) and around 11 eV for DFT + U calculations. Furthermore, the analyses of optical properties support the electronic properties of ceria. The elastic properties such as bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, Debye temperature, and Debye sound velocity were computed to investigate the mechanical properties of CeO2 and compared with the experimental and theoretical results. The result of elastic parameters found confirms that CeO2 is mechanically stable and has potential for a variety of different electronic applications.
      PubDate: Fri, 03 Jun 2022 10:20:01 +000
       
  • Compatibility of Environmentally Friendly Insulating Gases CF3I and c-C4F8
           with Cu Contacts

    • Abstract: The gas-solid compatibility between environmentally friendly insulating gas and copper contacts is worth studying. In this paper, based on density functional theory, the adsorption calculation of CF3I, c-C4F8, five typical decomposition gases, and Cu (1 1 1) surface was carried out. The adsorption energies, transferred charges, charge densities, and densities of states were calculated for different adsorption configurations. Research indicates that there is no obvious charge transfer between the I atom and the Cu atom in the four adsorption sites of Cu (1 1 1) for the CF3I molecule. There is a charge transfer between the F atoms and the Cu top surface. The electrons lost by Cu are transferred to F atoms. In the configurations of different adsorption positions on CF3I and Cu (1 1 1) planes, the top and bridge adsorption energies are −0.835 eV and −0.993 eV, respectively, which are chemical adsorption. Therefore, CF3I is most likely to form adsorption at the top or bridge site of the Cu (1 1 1) surface. The adsorption energy of c-C4F8 gas on Cu (1 1 1) surface is similar to that of CF3I at fcc and hcp sites. The absolute values are all less than 0.8 eV, and the van der Waals force is the main force. The adsorption energies of C2F4 and C3F6 in the five decomposed gases are −1.315 eV and −1.204 eV, respectively. The charge transfer is −0.32 eV and −0.45 eV, respectively. Their values are larger than those of the other gases studied, which belong to chemical adsorption. The smaller values of the remaining three gases belong to physical adsorption. All molecular structures and Cu (1 1 1) planes were not significantly deformed. From a microscopic point of view, the gas can better exist on the copper surface.
      PubDate: Sun, 29 May 2022 11:50:02 +000
       
  • Synthesis of Nickel-Zinc Ferrite Nanoparticles by the Sol-Gel
           Auto-Combustion Method: Study of Crystal Structural, Cation Distribution,
           and Magnetic Properties

    • Abstract: Spinel ferrite nanocomposites of Ni1–xZnxFe2O4 (x = 0.25 and 0.75) were synthesized by sol-gel auto-combustion and annealed between 250°C and 1000°C. A single-phase spinel structure was found through X-ray diffraction (XRD). The crystallite size is in the range of 17.55–66.98 nm, and lattice parameters are in the range of 8.351–8.434 Å. X-ray analysis revealed a slight shift of the peaks towards shorter angles when the zinc concentration increased from 0.25 to 0.75. XRD measurements revealed the metal ion distribution in the spinel ferrite system. For each sample, XRD data were used to compute structural characteristics such as lattice spacing, lattice constant, crystallite size, oxygen position parameter, tetrahedral and octahedral ionic radii, and bond lengths. Energy dispersive spectroscopy (EDS) spectra and field emission-electron scanning microscope (FESEM) were used to evaluate the elemental content and morphology. EDS analysis confirmed the presence of expected elements in the samples and confirmed the high doping rate of more than 180% of Zn ions in Ni ferrite. The evaluated particle sizes were determined to be 79.2 and 118.4 nm for zinc content of 0.25 and 0.75, respectively. The nearly spherical shape of the nanoparticles was shown in the transmission electron microscope (TEM). The magnetic moment, remanent, coercivity, and saturation magnetization were calculated by using vibrating sample magnetometer (VSM) results. The saturation magnetization magnitudes showed the influence of cation distribution.
      PubDate: Sat, 28 May 2022 06:50:01 +000
       
  • Single-Phase Silicate Phosphors (Ba1.3Ca0.7−xSiO4:xDy3+) Doped with
           Dysprosium for White Solid-State Lighting

    • Abstract: Single-phase phosphors have potential advantages such as simple processability, competitive cost, and other optical and optoelectronic properties. Hence, in this study, the silicate phosphors (Ba1.3Ca0.7−xSiO4:xDy3+) doped with Dy3+ ions (x = 0.01–0.05) were synthesized and characterized in detail. X-ray diffraction patterns showed that all the silicate phosphors have a τ-phase hexagonal unit cell independent of doping. However, d-spacing was reduced for the doped samples, indicating that the interplanar interactions were enhanced. Resultantly, the doped phosphors exhibited relatively larger domains with connectivity than the host, although there were sometimes microscale pores. Photoluminescence spectra stipulated that the optimized doping concentration is x = 0.03 for the silicate Ba1.3Ca0.7-xSiO4:xDy3+ phosphors. Finally, the CIE coordinates (0.30, 0.33) confirm that the Dy3+-doped silicate phosphors are well applicable to the white light-emitting diodes for solid-state lighting and display devices.
      PubDate: Tue, 24 May 2022 11:05:01 +000
       
  • Comparative Study on the Crystallite Size and Bandgap of Perovskite by
           Diverse Methods

    • Abstract: This research demonstrates the fast synthesis of CH3NH3PbBr3 perovskite powder via antisolvent addition and further thin-film synthesis by one-step spin coating. The structural and optical properties are investigated via X-ray diffraction, Fourier-transform infrared spectroscopy, and UV–Vis spectroscopy. Crystallite sizes are compared by three different size estimation techniques, which range between 95.8 nm and 105 nm. The perovskite showed a higher absorption coefficient over 104 cm−1 and a refractive index from 3.4 to 2.3 in the visible spectrum. The bandgap was estimated via three district methods, which revealed a very slightly varied bandgap in the range of 2.29 eV–2.32 eV.
      PubDate: Tue, 17 May 2022 12:35:03 +000
       
  • Synthesis of CoFe2O4/Graphene Oxide-Grafted Tetraethylenepentamine for
           Removal of Cr (VI) from Aqueous Solution

    • Abstract: In this study, amino-functionalized magnetic graphene-based composite TEPA-GO/CoFe2O4 (TGOM) was prepared by a simple one-step hydrothermal reaction and applied to the removal of Cr (VI) from wastewater. The removal of Cr (VI) by TGOM has the characteristics of high removal efficiency and excellent cycle performance. The maximum adsorption capacity is 114.81 mg/g, and the adsorption efficiency can still reach 62% after four cycles. The mass percentage of amino in TGOM material is about 1.97% according to thermogravimetric analysis. The modification by TEPA increased the adsorption sites and improved the adsorption capacities due to the synergistic effect of chelation with Cr (VI). The effects of pH, contact time, and temperature on the removal of Cr (VI) were studied. The removal process accorded with the pseudo-second-order kinetics and Langmuir isotherm model, and the thermodynamic parameters showed that the adsorption process was exothermic and spontaneous. The characterization analysis before and after adsorption showed that there were complexation reaction, electrostatic adsorption, and reduction mechanism in the removal process. The above results indicate that TGOM is an effective adsorption material for the removal of Cr (VI) in wastewater.
      PubDate: Fri, 13 May 2022 23:50:03 +000
       
  • Adsorption of Water Molecule in Graphene/MoS2 Heterostructure with Vacancy
           Defects in Mo Sites

    • Abstract: First-principle calculations based on the spin-polarized density functional theory (DFT) with vdW corrections by DFT-D2 approach have been carried out to study structural, electronic, and magnetic properties of water-adsorbed graphene/MoS2 heterostructures (system-I), and water-adsorbed graphene/MoS2 heterostructures with vacancy defects in Mo sites (systems-II). We consider vacancy defects in different Mo sites such as centre-1Mo atom vacancy defect (system-IIa), left-1Mo atom vacancy defect (system-IIb), and 2Mo atom vacancy defects (system-IIc). All the systems considered in this study are structurally stable; however, the stability of defected systems decreases with an increase in defect concentrations. The calculated binding energies of HS used in this study agree with the reported work. Electronic properties of system-I and systems-II reveal that they have metallic characteristics. Our investigation shows that system-I is nonmagnetic and systems-II are magnetic. The magnetic moment in the defected systems (system-IIa, system-IIb, and system-IIc) is developed by unpaired up and down-spins of electrons created in the orbitals of atoms due to vacancy defects in Mo atoms.
      PubDate: Mon, 11 Apr 2022 07:35:02 +000
       
  • Oxygen Dependence of Formation, Electronic State Transition, and Spin
           Polarization for Anatase TiO2: A Comprehensive Study

    • Abstract: The stability, geometry, microstructure, and specie combination together with the electronic states of the anatase TiO2 with oxygen defect content of 0%, 3.125%, 6.25%, and 12.5% have been intensively studied within the framework of the density functional theory method. The results show that the TiO2 with an oxygen defect is not as stable as intrinsic TiO2. The compound formation enthalpy Ef and the oxygen defect formation energy value tend to be larger for a higher defect content, and the oxygen defect gets harder to be formed. The bonds within the TiO6 polyhedron are different and not geometrically symmetrical. The bond strengths show distinct diversity, and the primitive cell of anatase TiO2 show spatial expansion when there are oxygen defects. All bands moved down to the low energy region, and two impurity energy band levels emerged for the anatase TiO2 with oxygen defect. The energy band gap is decreased from 3.085 eV to 1.165 eV, 1.0015 eV, and 0.43 eV. There are generally 7 peaks for the spin density of states function, corresponding to their 5 main bands. For the anatase TiO2 with an oxygen defect content of 12.5%, the spin density of states functions are not horizontal ordinate symmetrical near −1.12 eV and 0.31 eV. They are formed by oxygen defect energy levels, which is the result of the Ti d and O p state electron polarization. Transitions from weak paramagnetic to antiferromagnetic are found for the anatase TiO2 with oxygen defect.
      PubDate: Mon, 11 Apr 2022 07:35:02 +000
       
  • Quantum Dot Phase Transition Simulation with Hybrid Quantum Annealing via
           Metropolis-Adjusted Stochastic Gradient Langevin Dynamics

    • Abstract: We report a hybrid quantum-classical simulation approach for simulating the optical phase transition observed experimentally in the ultrahigh-density type-II InAs quantum dot array. A hybrid simulation scheme, which contains stochastic gradient Langevin dynamics (a well-known Bayesian machine learning algorithm for big data) along with adiabatic quantum annealing, is developed to reproduce the experimentally observed phase transition. By implementing the simulation scheme into a quantum circuit, we successfully verified the phase transition observed in the experiment. Our work demonstrates for the first time the feasibility of hybridizing quantum computation with classical Langevin dynamics for the analysis of carrier dynamics and quantum phase transition of the quantum dot.
      PubDate: Mon, 11 Apr 2022 07:35:02 +000
       
  • AlGaN/GaN Heterostructure Schottky Barrier Diodes with Graded Barrier
           Layer

    • Abstract: The AlGaN/GaN Schottky barrier diodes (SBDs) working as high-power mixer and multiplier show great potential in millimeter wave (MMW) field owing to their high breakdown voltage. Nevertheless, its further application is severely limited by large reverse leakage current (Jr) since the two-dimensional electron gas (2DEG) channel is hard to be pinched off at low voltage. To address this limitation, a graded AlGaN/GaN heterostructure is introduced to extend the 2DEG channel into a quasi-three-dimensional electron slab. By comparing the fixed Al composition AlGaN/GaN SBD, Jr of the graded AlGaN/GaN SBD is significantly reduced due to the extension of channel carriers, confirming the effective Jr suppression effect of this structure. Furthermore, on this basis, a recessed anode structure is utilized to expect a smaller Jr. The results indicated that the graded AlGaN/GaN SBDs with air-bridge structure have achieved a pretty low Jr value (1.6 × 10−13 A at -15 V), and its cutoff frequency is as high as 60.6 GHz. It is expected that such SBDs with low Jr have significant advantages in future applications.
      PubDate: Wed, 06 Apr 2022 09:05:01 +000
       
  • Study on the Adsorption Characteristics of Mo-Doped Graphene on the
           Decomposition Products of SF6 Substitute Gas Based on First-Principle
           Calculations

    • Abstract: C4F7N, C5F10O, etc., as new environmental-friendly alternative gases decompose under partial discharge and produce a series of products such as CO, CF4, C2F6, C3F8, CF3CN, C2F5CN, and COF2. Based on the first-principles calculation method of density functional theory (DFT), the adsorption characteristics of intrinsic state graphene and Mo-doped graphene adsorbing SF6 and its substitute gas decomposition products are calculated and analyzed. By comparing the adsorption energy, adsorption distance, density of state, Mulliken charge population, charge transfer amount, and molecular orbital energy for adsorbing different decomposition gases, it can be seen that the system structure is the most stable when Mo is doped at the T site of the graphene surface. The adsorption of Mo-doped graphene on gas molecules is significantly stronger than that of intrinsic graphene, and the order of adsorption is: SO2F2 > H2S > SO2 > CF4. The adsorption of H2S gas molecules by intrinsic state and Mo-doped graphene is n-type adsorption, while the adsorption of SO2F2, CF4, and SO2 gas molecules is p-type adsorption. Mo-doped graphene can be used as a detection device for SO2F2 gas resistance sensors.
      PubDate: Sun, 27 Mar 2022 12:20:02 +000
       
  • Electric Modulus Analysis of (1 − x)
           PbMg1/3Nb2/3O3-(x)K1/2Bi1/2TiO3 Ceramics

    • Abstract: Ferroelectrics refer to groups of dielectrics having the property of spontaneous polarization. Lead magnesium niobate-potassium bismuth titanate ((1 − x) PbMg1/3Nb2/3O3-(x)K1/2Bi1/2TiO3)) x = 0.15, 0.25, and 0.35 are prepared by solid-state reaction rout technique. The electric modulus of the prepared samples is studied using the complex impedance spectroscopic method at 400°C, 450°C, and 500°C in various frequency ranges. In the lower frequency range, the real modulus (M′ (ω)) decreased with increasing the temperature. Furthermore, the real modulus (M′ (ω)) increased with increasing frequency and the concentration of the doping component. The imaginary modulus (M″ (ω)) increased with increasing the temperature. The significant variations in the real and imaginary coefficients signify the existence of thermally activated dielectric relaxation between the selected components. Moreover, the magnitude of grain capacitance increased with increasing the temperature, confirming the negative temperature coefficient of resistance of the material.
      PubDate: Tue, 22 Mar 2022 09:20:01 +000
       
  • Study of the Effect of Quenching on Microstructural and Magnetic
           Properties of Cu-Doped Mg-Ferrite

    • Abstract: Mg1-xCuxFe2O4 (x = 0.0–0.5) was prepared by the double sintering ceramic method, which sintered at 1100°C and 1200°C for 3 hours and investigated for structural, microstructural, and magnetic properties as a function of the Cu content and cooling process. XRD analysis of 1100°C sintered samples revealed that all the samples were crystallized in a single-phase cubic spinal structure. The microstructural and magnetic properties of slow cooled (furnace-cooled) and fast cooled (quenched) Mg-Cu ferrites have been studied using the scanning electron microscope (SEM), vibrating sample magnetometer (VSM), and Mössbauer spectroscopy after sintering at 1200°C. Homogeneous coaxial grains did not form for any furnace-cooled samples, while for the quenched sample, homogeneous grains were clearly visible even without doping with Cu. Substantial grain growth was witnessed by the samples with higher copper content for both cooling conditions, whereas quenched samples possessed a smaller grain size compared to furnace-cooled samples. The saturation magnetization experienced a higher value for quenched samples compared to furnace-cooled samples with increasing Cu content except for x = 0.4. The sextet pattern of Mössbauer spectroscopy confirmed all the samples were ferromagnetic in nature. Chemical shift, quadrupole shift, hyperfine field, and site occupancy of Fe3+ were also obtained using Mössbauer spectroscopy.
      PubDate: Sun, 27 Feb 2022 10:05:02 +000
       
  • Evolution of Microstructure during Rapid Solidification of SiC under High
           Pressure

    • Abstract: The microstructure evolution of liquid silicon carbide (SiC) during rapid solidification under different pressure values is simulated with the Tersoff potential using molecular dynamics. The structure evolution characteristics of SiC are analyzed by considering the pair distribution function, bond angle distribution, coordination number, and the diagrams of the microstructure during rapid solidification. The results show that the average energy of atoms gradually increases with pressure. When the pressure reaches 100 GPa, the average energy of the atom is greater than the average energy of the atom in the initial liquid state. Under different pressures, the diffusion of atoms tends to remain stable at a temperature of about 3700 K. The application of pressure has a major impact on the arrangement of atoms, except on the third-nearest neighbor, while the impact on the nearest neighbor and the second-nearest neighbor is relatively small. The pressure increases the medium-range order of the system. The coordination numbers of Si and C atoms gradually decrease with the decrease in temperature and increase in pressure. Pressure changes the microstructure of the SiC amorphous system after solidification, and the density can be increased by adjusting the coordination number of atoms. As the pressure increases, the SiC amorphous system exhibits a dense structure with coordination numbers of 4, 5, 6, and 7.
      PubDate: Wed, 23 Feb 2022 09:05:02 +000
       
  • Equation of State Determination for Rhenium Using First-Principles
           Molecular Dynamics Calculations and High-Pressure Experiments

    • Abstract: The room-temperature bulk modulus of rhenium (Re) was measured in the pressure range 0 to 115 GPa using a laser-annealing diamond anvil cell and the synchrotron X-ray diffraction method. Thermal properties of Re were investigated up to 4000 K based on first-principles molecular dynamics calculations, and the equation of state for Re was determined using experimental and calculated data. A Vinet equation of state fitted to the 300 K data yielded a bulk modulus of KT0 = 384 GPa and a pressure derivative of  = 3.26. The contribution of thermal pressure was determined to have the form ΔPth = [αKT(Va) + (∂KT/∂T)Vln(Va/V)]ΔT. When αKT(Va) was assumed to be constant, the fit to the data yielded αKT(Va) = 0.0056 GPa/K. In contrast, the volume dependence of the thermal pressure was very small, and fitting yielded a value of (∂KT/∂T)V = −0.00042.
      PubDate: Fri, 18 Feb 2022 08:50:01 +000
       
  • First-Principles Calculations to Investigate the Mechanical Structure and
           Optical Properties of Lead Halide Perovskite CH3NH3PbI3

    • Abstract: We report the study of the mechanical structure and optical properties of lead halide perovskite CH3NH3PbI3 using ab initio methods. The ground state energy calculations were performed within density functional theory and generalized gradient approximation using the pseudopotential method with plane-wave basis sets. The norm conserving pseudopotential was used. The ground state properties of the electronic structure of the perovskite were used and elastic parameters such as bulk modulus B, Young’s modulus E, shear modulus G, and Poisson’s ratio were determined and found to be in good agreement with experimental values. The ratio obtained was found to be greater than 1.75. Poisson’s ratio () was obtained as 0.25 implying that CH3NH3PbI3 is a ductile material. The absorption coefficient within the energy range of 0 to 6 eV was found to be 5.76 × 105 cm−1 indicating maximum absorption. The absorption coefficient compares well with the available experimental and computed values.
      PubDate: Wed, 16 Feb 2022 07:20:00 +000
       
  • Computational Study of Metal-Free Magnetism and Spin-Dependent Seebeck
           Effect in Silicene Nanoribbons with Zigzag and Klein Edges

    • Abstract: Nanoribbons based on low-dimensional materials are potential candidates for nanoscale spintronics devices. Here, some ferromagnetic silicene nanoribbons with zigzag and Klein edges (N-ZKSiNRs) are constructed. It is demonstrated that the N-ZKSiNRs with various widths (N) are placed in various spin-resolved electronic situations. With the increase of the width parameter N from 4 to 19, the N-ZKSiNRs pass from the indirect-gap bipolar magnetic semiconducting state (BMS) to the bipolar spin-gapless semiconductor (BSGS) and eventually to half-metallicity (HM). Moreover, applying a temperature gradient through the nanoribbons leads to spin-dependent current with the opposite flowing and spin orientations, demonstrating the spin-dependent Seebeck effect (SDSE). Besides, it was found that the BSGS phase is superior to the BMS and HM for generating SDSE. These findings confirm that the ZKSiNRs are promising choices for spin caloritronics devices.
      PubDate: Sat, 12 Feb 2022 07:20:03 +000
       
  • An Effective Route for the Growth of Multilayer MoS2 by Combining Chemical
           Vapor Deposition and Wet Chemistry

    • Abstract: Molybdenum disulfide (MoS2) is an actively pursuing material of the 2D family due to its semiconducting characteristics, making it a potential candidate for nano and optoelectronics application. MoS2 growth from molybdenum and sulphur precursors by chemical vapor depositions (CVD) is used widely, but molybdates’ conversion into MoS2 via CVD is overlooked previously. Direct growth of MoS2 on the desired pattern not only reduces the interfacial defects but also reduces the complexities in device fabrication. In this work, we combine the wet synthesis and chemical vapor deposition method where sodium molybdate and L-cysteine are used to make a solution. With the dip coating, the mixture is coated on the substrates, and then, chemical vapor deposition is used to convert the chemicals into MoS2. Raman spectroscopy revealed the presence of oxysulphides (peaks number value) other than and , where heat treatment was performed in the presence of Ar gas flow only. On the other hand, the films reducing in the presence of sulphur and argon gas promote only and peaks of MoS2, which confirms complete transformation. XRD diffraction showed a very small change in the diffraction peaks and value of strain, whereas SEM imaging showed the flakes formation for MoS2 samples which were heated in the presence of sulphur. X-ray photoelectron spectroscopy is also performed for the chemical composition and to understand the valence state of Mo, S, and O and other species.
      PubDate: Wed, 09 Feb 2022 06:50:01 +000
       
  • Zinc-Blende GeC Stabilized on GaN (001): An Ab Initio Study

    • Abstract: First-principle calculations have been performed to explore the initial stages of the zinc blende-like germanium carbide epitaxial growth on the gallium nitride (001)-(2 × 2) surface. First, we studied the Ge/C monolayer adsorption and incorporation at high symmetry sites. Results show that the adsorptions at the top and hcp1 sites are the most stable structures of C and Ge, respectively. Different terminated surfaces were used on the GeC epitaxial growth. According to the surface formation energies, only the first two bilayers are stable; therefore, the GeC epitaxial growth is favorable only under N-rich conditions on a Ge-terminated surface and with Ge bilayers terminated. In addition, it is demonstrated that GeC bilayers on the C-terminated surfaces are unstable and preclude the epitaxial growth. Electronic properties have been investigated by calculating the density of states (DOS) and the projected density of states (PDOS) of the most favorable structures.
      PubDate: Sun, 30 Jan 2022 13:20:04 +000
       
  • Facile Synthesis of Graphene Oxide/Titanate Nanotube Composites and Their
           Application for Cobalt(II) Removal

    • Abstract: In this work, the novel graphene oxide/titanate nanotubes (GTNT) composites were synthesized through a facile and high-yield alkaline hydrothermal method. SEM, TEM, XRD, BET, and TGA/DTA were applied to study the morphology and structure of the GTNT composites. The results show that a huge number of titanate nanotubes are closely attached to the graphene sheet structure and overlap each other. This hierarchical morphology endows the GTNT composites with not only the high specific surface area of 236.9 m2/g but also abundant porous structure, both of which are benefit for Co(II) adsorption. The batch adsorption experiments demonstrate that the GTNT composites have a high adsorption capacity and rapid kinetics for Co(II) adsorption (10 min for equilibrium). The adsorption capacity of the GTNT composites reaches 211.1 mg/g. The adsorption kinetics of the GTNT composites fits well to the pseudo-second-order model, while the adsorption isotherm of which fits well to the Langmuir model. The adsorption performance of Co(II) ions on the GTNT composites has a great relationship with the pH value, in the pH range of 1–7, the Co(II) adsorption capacity of the GTNT composites greatly increases with the increase of the pH value. In addition, the effect of coexisting anions on fluoride removal is also investigated. Na+, K+, and Mg2+ ions have shown a negligible effect on the Co(II) adsorption efficiency of the GTNT composites. However, the existences of Cu2+, Cd2+, and Pb2+ ions would clearly have an effect on the Co(II) adsorption of the GTNT composites. The adsorption mechanism is also discussed. It is believed that the GTNT composites can be considered as a potential functional material for removing the radioactive metals containing wastewater.
      PubDate: Fri, 28 Jan 2022 11:35:02 +000
       
  • Analogous Atomic and Electronic Properties between and Defects in
           Hexagonal Boron Nitride

    • Abstract: We investigate defect properties in hexagonal boron nitride (hBN) which is attracting much attention as a single photon emitter. Using first-principles calculations, we find that nitrogen-vacancy defect has a lower energy structure in symmetry in 1− charge state than the previously known symmetry structure. Noting that carbon has one more valence electron than boron species, our finding naturally points to the correspondence between and defects with one charge state difference between them, which is indeed confirmed by the similarity of atomic symmetries, density of states, and excitation energies. Since is considered as a promising candidate for the source of single photon emission, our study suggests as another important candidate worth attention, with its simpler form without the incorporation of foreign elements into the host material.
      PubDate: Tue, 11 Jan 2022 04:50:00 +000
       
  • A -Type Magnetic Semiconductor (Sr, Na)(Zn, Mn)2Sb2 Isostructural to
           122-Type Iron-Based Superconductors

    • Abstract: A new diluted magnetic semiconductor (Sr, Na)(Zn, Mn)2Sb2 has been successfully synthesized by doping Na and Mn into the parent compound , which has a -type crystal structure (space group , No. 164, ) isostructural to the 122-type iron-based superconductor . No magnetic ordering has been observed when only spins are doped by (Zn, Mn) substitution. Only with carriers codoped by (Sr, Na) substitution, a ferromagnetic ordering occurs below the maximum Curie temperature ∼9.5 K. Comparing with other -type diluted magnetic semiconductors, we will show that negative chemical pressure suppresses the Curie temperature.
      PubDate: Mon, 10 Jan 2022 06:50:02 +000
       
 
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