The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Vitaly I. Konov - One of the best experts on this subject based on the ideXlab platform.
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mid IR Reflectance Spectrum of multilayer graphene influence of adsorbate at the graphene substrate interface
Quantum Electronics, 2019Co-Authors: V. D. Frolov, Pavel A. Pivovarov, Victor G. Plotnichenko, Vitaly I. KonovAbstract:Water adsorbate at the interface between graphene and SiO2/Si substrate is found to affect the Reflectance spectra of (3 – 6)-layer graphene in the mid-IR range (λ = 2 – 16 μm). The sample under study was previously kept in acetone vapour to remove water adsorbate from the graphene – substrate interface. The graphene Reflectance in the range of 8–16 μm tends to decrease with recovery of water adsorbate layer at the graphene – substrate interface at room temperature and relative aIR humidity RH = 40% – 60%. The observed effect is most likely caused by the blue shift of the absorption edge at interband transitions due to the change in the Fermi level position in the graphene valence band under the influence of the charge induced in graphene by the water adsorbate film.
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Mid-IR Reflectance Spectrum of multilayer graphene: Influence of adsorbate at the graphene – substrate interface
Quantum Electronics, 2019Co-Authors: V. D. Frolov, Pavel A. Pivovarov, Victor G. Plotnichenko, Vitaly I. KonovAbstract:Water adsorbate at the interface between graphene and SiO2/Si substrate is found to affect the Reflectance spectra of (3 – 6)-layer graphene in the mid-IR range (λ = 2 – 16 μm). The sample under study was previously kept in acetone vapour to remove water adsorbate from the graphene – substrate interface. The graphene Reflectance in the range of 8–16 μm tends to decrease with recovery of water adsorbate layer at the graphene – substrate interface at room temperature and relative aIR humidity RH = 40% – 60%. The observed effect is most likely caused by the blue shift of the absorption edge at interband transitions due to the change in the Fermi level position in the graphene valence band under the influence of the charge induced in graphene by the water adsorbate film.
R. Dovesi - One of the best experts on this subject based on the ideXlab platform.
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Quantum-mechanical Simulation of the IR Reflectance Spectrum of Mn 3 Al 2 Si 3 O 12 Spessartine
2015Co-Authors: Anna Maria Ferrari, R. Demichelis, Fabien Pascale, A. Meyer, L. Maschio, R. DovesiAbstract:The Reflectance Spectrum of one member of the garnet family, Mn3Al2Si3O12 spessartine, was computed at the ab initio level with an all electron Gaussian type basis set and the B3LYP Hamiltonian. The static high frequency dielectric constant was obtained by applying the Coupled Perturbed Kohn Sham scheme as implemented in the CRYSTAL code; the Hessian matrix was evaluated numerically starting from the analytical gradients of the total energy with respect to the Cartesian coordinates of the atoms; the oscillator strengths were computed from well localized Wannier functions. An excellent agreement was obtained with the corresponding experimental Spectrum, the exception being the very low frequency region.
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the infrared Spectrum of ortho enstatite from Reflectance experiments and fIRst principle simulations
Monthly Notices of the Royal Astronomical Society, 2012Co-Authors: R. Demichelis, Hiroshi Suto, Yves Noel, H Sogawa, Takahiro Naoi, C Koike, H Chihara, Norimasa Shimobayashi, Matteo Ferrabone, R. DovesiAbstract:Infrared (IR) spectra provide a rich amount of information concerning chemical composition, lattice structure, size and shape of cIRcumstellar dust. Accurate reference data are then requIRed for the analysis of the various detected components. This study provides the IR characterization of one of the most frequently observed compounds, MgSiO3 ortho-enstatite, and shows that IR experiments and ab initio techniques can be used synergically to obtain high-quality data concerning crystalline materials. The IR Reflectance Spectrum of synthetic ortho-enstatite was collected and compared to ab initio results (Gaussian-type basis set, PBE0 hybrid density functional theory (DFT) functional). An excellent agreement is observed both for vibrational frequencies (ν) and intensities, the latter estimated through the oscillator strength. The mean absolute difference between experimental and calculated ν is of the order of 7–8 cm−1 (43 out of 65 peaks differ by less than 10 cm−1, only four peaks differ by 15–19 cm−1). The static dielectric tensor and its components (electronic and ionic contributions) were measured and compared to calculated data: differences are in the 2–5 per cent range.
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Quantum-mechanical simulation of the IR Reflectance Spectrum of Mn3Al2Si3O12 spessartine
2010Co-Authors: Anthony Ferrari, R. Demichelis, Fabien Pascale, A. Meyer, L. Maschio, R. DovesiAbstract:The Reflectance Spectrum of one member of the garnet family, Mn3Al2Si3O12 spessartine, was computed at the ab initio level with an all electron Gaussian type basis set and the B3LYP Hamiltonian. The static high frequency dielectric constant was obtained by applying the Coupled Perturbed Kohn Sham scheme as implemented in the CRYSTAL code; the Hessian matrix was evaluated numerically starting from the analytical gradients of the total energy with respect to the Cartesian coordinates of the atoms; the oscillator strengths were computed from well localized Wannier functions. An excellent agreement was obtained with the corresponding experimental Spectrum, the exception being the very low frequency region.
Pavel A. Pivovarov - One of the best experts on this subject based on the ideXlab platform.
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mid IR Reflectance Spectrum of multilayer graphene influence of adsorbate at the graphene substrate interface
Quantum Electronics, 2019Co-Authors: V. D. Frolov, Pavel A. Pivovarov, Victor G. Plotnichenko, Vitaly I. KonovAbstract:Water adsorbate at the interface between graphene and SiO2/Si substrate is found to affect the Reflectance spectra of (3 – 6)-layer graphene in the mid-IR range (λ = 2 – 16 μm). The sample under study was previously kept in acetone vapour to remove water adsorbate from the graphene – substrate interface. The graphene Reflectance in the range of 8–16 μm tends to decrease with recovery of water adsorbate layer at the graphene – substrate interface at room temperature and relative aIR humidity RH = 40% – 60%. The observed effect is most likely caused by the blue shift of the absorption edge at interband transitions due to the change in the Fermi level position in the graphene valence band under the influence of the charge induced in graphene by the water adsorbate film.
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Mid-IR Reflectance Spectrum of multilayer graphene: Influence of adsorbate at the graphene – substrate interface
Quantum Electronics, 2019Co-Authors: V. D. Frolov, Pavel A. Pivovarov, Victor G. Plotnichenko, Vitaly I. KonovAbstract:Water adsorbate at the interface between graphene and SiO2/Si substrate is found to affect the Reflectance spectra of (3 – 6)-layer graphene in the mid-IR range (λ = 2 – 16 μm). The sample under study was previously kept in acetone vapour to remove water adsorbate from the graphene – substrate interface. The graphene Reflectance in the range of 8–16 μm tends to decrease with recovery of water adsorbate layer at the graphene – substrate interface at room temperature and relative aIR humidity RH = 40% – 60%. The observed effect is most likely caused by the blue shift of the absorption edge at interband transitions due to the change in the Fermi level position in the graphene valence band under the influence of the charge induced in graphene by the water adsorbate film.
V. D. Frolov - One of the best experts on this subject based on the ideXlab platform.
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mid IR Reflectance Spectrum of multilayer graphene influence of adsorbate at the graphene substrate interface
Quantum Electronics, 2019Co-Authors: V. D. Frolov, Pavel A. Pivovarov, Victor G. Plotnichenko, Vitaly I. KonovAbstract:Water adsorbate at the interface between graphene and SiO2/Si substrate is found to affect the Reflectance spectra of (3 – 6)-layer graphene in the mid-IR range (λ = 2 – 16 μm). The sample under study was previously kept in acetone vapour to remove water adsorbate from the graphene – substrate interface. The graphene Reflectance in the range of 8–16 μm tends to decrease with recovery of water adsorbate layer at the graphene – substrate interface at room temperature and relative aIR humidity RH = 40% – 60%. The observed effect is most likely caused by the blue shift of the absorption edge at interband transitions due to the change in the Fermi level position in the graphene valence band under the influence of the charge induced in graphene by the water adsorbate film.
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Mid-IR Reflectance Spectrum of multilayer graphene: Influence of adsorbate at the graphene – substrate interface
Quantum Electronics, 2019Co-Authors: V. D. Frolov, Pavel A. Pivovarov, Victor G. Plotnichenko, Vitaly I. KonovAbstract:Water adsorbate at the interface between graphene and SiO2/Si substrate is found to affect the Reflectance spectra of (3 – 6)-layer graphene in the mid-IR range (λ = 2 – 16 μm). The sample under study was previously kept in acetone vapour to remove water adsorbate from the graphene – substrate interface. The graphene Reflectance in the range of 8–16 μm tends to decrease with recovery of water adsorbate layer at the graphene – substrate interface at room temperature and relative aIR humidity RH = 40% – 60%. The observed effect is most likely caused by the blue shift of the absorption edge at interband transitions due to the change in the Fermi level position in the graphene valence band under the influence of the charge induced in graphene by the water adsorbate film.
R. Demichelis - One of the best experts on this subject based on the ideXlab platform.
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Quantum-mechanical Simulation of the IR Reflectance Spectrum of Mn 3 Al 2 Si 3 O 12 Spessartine
2015Co-Authors: Anna Maria Ferrari, R. Demichelis, Fabien Pascale, A. Meyer, L. Maschio, R. DovesiAbstract:The Reflectance Spectrum of one member of the garnet family, Mn3Al2Si3O12 spessartine, was computed at the ab initio level with an all electron Gaussian type basis set and the B3LYP Hamiltonian. The static high frequency dielectric constant was obtained by applying the Coupled Perturbed Kohn Sham scheme as implemented in the CRYSTAL code; the Hessian matrix was evaluated numerically starting from the analytical gradients of the total energy with respect to the Cartesian coordinates of the atoms; the oscillator strengths were computed from well localized Wannier functions. An excellent agreement was obtained with the corresponding experimental Spectrum, the exception being the very low frequency region.
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the infrared Spectrum of ortho enstatite from Reflectance experiments and fIRst principle simulations
Monthly Notices of the Royal Astronomical Society, 2012Co-Authors: R. Demichelis, Hiroshi Suto, Yves Noel, H Sogawa, Takahiro Naoi, C Koike, H Chihara, Norimasa Shimobayashi, Matteo Ferrabone, R. DovesiAbstract:Infrared (IR) spectra provide a rich amount of information concerning chemical composition, lattice structure, size and shape of cIRcumstellar dust. Accurate reference data are then requIRed for the analysis of the various detected components. This study provides the IR characterization of one of the most frequently observed compounds, MgSiO3 ortho-enstatite, and shows that IR experiments and ab initio techniques can be used synergically to obtain high-quality data concerning crystalline materials. The IR Reflectance Spectrum of synthetic ortho-enstatite was collected and compared to ab initio results (Gaussian-type basis set, PBE0 hybrid density functional theory (DFT) functional). An excellent agreement is observed both for vibrational frequencies (ν) and intensities, the latter estimated through the oscillator strength. The mean absolute difference between experimental and calculated ν is of the order of 7–8 cm−1 (43 out of 65 peaks differ by less than 10 cm−1, only four peaks differ by 15–19 cm−1). The static dielectric tensor and its components (electronic and ionic contributions) were measured and compared to calculated data: differences are in the 2–5 per cent range.
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Quantum-mechanical simulation of the IR Reflectance Spectrum of Mn3Al2Si3O12 spessartine
2010Co-Authors: Anthony Ferrari, R. Demichelis, Fabien Pascale, A. Meyer, L. Maschio, R. DovesiAbstract:The Reflectance Spectrum of one member of the garnet family, Mn3Al2Si3O12 spessartine, was computed at the ab initio level with an all electron Gaussian type basis set and the B3LYP Hamiltonian. The static high frequency dielectric constant was obtained by applying the Coupled Perturbed Kohn Sham scheme as implemented in the CRYSTAL code; the Hessian matrix was evaluated numerically starting from the analytical gradients of the total energy with respect to the Cartesian coordinates of the atoms; the oscillator strengths were computed from well localized Wannier functions. An excellent agreement was obtained with the corresponding experimental Spectrum, the exception being the very low frequency region.
