A new molecular spectroscopic database for high-temperature modeling of the spectra of molecules in the gas phase is described. This database, called HITEMP, is analogous to the HITRAN database but ...encompasses many more bands and transitions than HITRAN for the absorbers H
2O, CO
2, CO, NO, and OH. HITEMP provides users with a powerful tool for a great many applications: astrophysics, planetary and stellar atmospheres, industrial processes, surveillance, non-local thermodynamic equilibrium problems, and investigating molecular interactions, to name a few. The sources and implementation of the spectroscopic parameters incorporated into HITEMP are discussed.
We present a high-resolution, high-temperature version of the Carbon Dioxide Spectroscopic Databank called CDSD-4000. The databank contains the line parameters (positions, intensities, air- and ...self-broadened half-widths, coefficients of temperature dependence of air- and self-broadened half-widths, and air-broadened pressure shifts) of the four most abundant isotopologues of CO
2. A reference temperature is 296
K and an intensity cutoff is 10
−27
cm
−1/molecule
cm
−2 at 4000
K. The databank has 628,324,454 entries, covers the 226–8310
cm
−1 spectral range and designed for the temperature range 2500–5000
K. Format of CDSD-4000 is similar to that of HITRAN-2008. The databank has been generated within the framework of the method of effective operators and based on the global fittings of spectroscopic parameters (parameters of the effective Hamiltonians and effective dipole moment operators) to observed data collected from the literature. The databank is useful for studying high-temperature radiative properties of CO
2, including exoplanets atmospheres, aerothemal modeling for Mars entry missions, high-temperature laboratory spectra, and industrial applications. CDSD-4000 is freely accessible via the Internet site
ftp://ftp.iao.ru/pub/CDSD-4000.
► We present a high-temperature infrared spectroscopic CO
2 databank called CDSD-4000. ► CDSD-4000 can be used to study radiative properties for temperatures 2500–5000
K. ► CDSD-4000 is freely accessible at
ftp://ftp.iao.ru/pub/CDSD-4000.
In the present article, we give a review of modern data and latest achievements pertaining to the study of electronic properties of oxygen vacancies in hafnium oxide. Hafnium oxide is a key ...dielectric for use in many advanced silicon devices. Oxygen vacancies in hafnium oxide largely determine the electronic properties of the material. We show that the electronic transitions between the states due to oxygen vacancies largely determine the optical absorption and luminescent properties of hafnium oxide. We discuss the role of oxygen vacancies as traps that facilitate charge transport in hafnium oxide films. Also, we demonstrate the fact that the electrical conductivity in hafnium oxide is controlled by the phonon-assisted tunnelling of charge carriers between traps that were identified as oxygen vacancies.
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•GEISA-2020 database release: 6,746,987 entries in the line parameters database.•23 molecules updated and 6 new molecules added (HONO, COFCl, CH3F, CH3I, RuO4, H2C3H2 (isomer of ...C3H4).•Evaluation of the spectroscopic parameters through radiative transfer simulations compared to atmospheric spectra (SPARTE chain).
This paper describes the 2020 release of the GEISA database (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information), developed and maintained at LMD since 1974. GEISA is the reference database for several current or planned Thermal and Short-Wave InfraRed (TIR and SWIR) space missions IASI (Infrared Atmospheric Sounding Interferometer), IASI-NG (IASI New Generation), MicroCarb (Carbon Dioxide Monitoring Mission), Merlin (MEthane Remote sensing LIdar missioN). It is actually a compilation of three databases: the “line parameters database”, the “cross-section sub-database” and the “microphysical and optical properties of atmospheric aerosols sub-database”. The new edition concerns only the line parameters dataset, with significant updates and additions implemented using the best available spectroscopic data.
The GEISA-2020 line parameters database involves 58 molecules (145 isotopic species) and contains 6,746,987 entries, in the spectral range from 10−6 to 35877 cm−1. In this version, 23 molecules have been updated (with 10 new isotopic species) and 6 new molecules have been added (HONO, COFCl, CH3F, CH3I, RuO4, H2C3H2 (isomer of C3H4)) corresponding to 15 isotopic species. The compilation can be accessed through the AERIS data and services center for the atmosphere website (https://geisa.aeris-data.fr/), with the development of a powerful graphical tool and convenient searching, filtering, and plotting of data using modern technologies (PostgreSQL database, REST API, VueJS, Plotly).
Based on four examples (H2O, O3, O2 and SF6), this paper also shows how the LMD in house validation algorithm SPARTE (Spectroscopic Parameters And Radiative Transfer Evaluation) helps to evaluate, correct, reject or defer the input of new spectroscopic data into GEISA and this, thanks to iterations with researchers from different communities (spectroscopy, radiative transfer).
The atmosphere of Mars is dominated by CO2, making it a natural laboratory for studying CO2 spectroscopy. The Atmospheric Chemistry Suite (ACS) on board the ExoMars Trace Gas Orbiter uses solar ...occultation geometry to search for minor atmospheric species. During the first year of ACS observations, the attention was focused on the spectral range covering the methane ν3 absorption band, 2900–3300 cm−1, which has previously been observed on Mars. No methane was detected by ACS; instead, an improvement of the data processing has led to the identification of 30 weak absorption lines that were missing from spectroscopic databases. Periodic series of absorptions up to ~1.6% deep are observed systematically around the position of the methane Q-branch when the line of sight penetrates below 20 km (creating an optical path length of 300–400 km, with an effective pressure of a few millibar). The observed frequencies of the discovered lines match theoretically computed positions of the P-, Q-, and R-branches of the magnetic dipole and electric quadrupole 01111-00001 (ν2 + ν3) absorption bands of the main CO2 isotopologue; neither band has been measured or computed before. The relative depths of the observed spectral features support the magnetic dipole origin of the band. The contribution of the electric quadrupole absorption is several times smaller. Here we report the first observational evidence of a magnetic dipole CO2 absorption.
The HITRAN2020 molecular spectroscopic database Gordon, I.E.; Rothman, L.S.; Hargreaves, R.J. ...
Journal of Quantitative Spectroscopy & Radiative Transfer/Journal of quantitative spectroscopy & radiative transfer,
01/2022, Letnik:
277
Journal Article
Recenzirano
Odprti dostop
•The HITRAN2020 molecular spectroscopic database and its validations are presented.•Extended line-by-line coverage to 55 molecules, with new isotopologues included.•Increased spectral and dynamic ...ranges for multiple molecules.•Quality and amount of spectral parameters (including sophisticated line shapes) is increased.•Updates to cross sections, CIA, software tools & auxiliary data also described.
The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years).
All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules.
The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition.
The atomic and electronic structure of nonstoichiometric oxygen-deficient tantalum oxide TaOx<2.5 grown by ion beam sputtering deposition was studied. The TaOx film content was analyzed by x-ray ...photoelectron spectroscopy and by quantum-chemistry simulation. TaOx is composed of Ta2O5, metallic tantalum clusters and tantalum suboxides. A method for evaluating the stoichiometry parameter of TaOx from the comparison of experimental and theoretical photoelectron valence band spectra is proposed. The charge transport properties of TaOx were experimentally studied and the transport mechanism was quantitatively analyzed with four theoretical dielectric conductivity models. It was found that the charge transport in almost stoichiometric and nonstoichiometric tantalum oxide can be consistently described by the phonon-assisted tunneling between traps.
We present an atmospheric version, CDSD-296, of the carbon dioxide spectroscopic databank (CDSD). The databank contains the calculated line parameters (positions, intensities, air- and self-broadened ...half-widths, coefficients of temperature dependence of air-broadened half-widths and air pressure-induced line shifts) of the twelve stable isotopic species of CO2. The reference temperature is Tref=296K and the intensity cutoff is Icut=10−30cm−1/(moleculecm−2). More than 500,000 lines covering the 6–14,075cm−1 spectral range are included in CDSD-296. The databank has been generated within the framework of the method of effective operators and based on the global weighted fits of spectroscopic parameters (parameters of the effective Hamiltonians and effective dipole moment operators) to observed data collected from the literature. The fitted models are able to reproduce known measured positions and intensities with accuracies compatible with measurement uncertainties. The line-shape parameters originate from the recent theoretical and semi-empirical calculations. Comparisons of CDSD-296 with HITRAN-2012, GEISA-2011, and the AMES line lists are also given.
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•CDSD-296 is aimed at atmospheric applications.•CDSD-296 contains data of all 12 stable CO2 isotopologues.•CDSD-296 is based on global fits of measured line positions and intensities.•CDSD-296 contains calculated line parameters for the 6–14,075cm−1 spectral range.
The influence of oxygen content in active zirconium oxide layers on the electrophysical properties of TaN/ZrOx/Ni memristors is investigated. The O/Zr atomic ratio (x) in the oxide layers was varied ...in the range from 1.56 to 2.0 by changing the partial oxygen pressure during their deposition by ion-beam sputtering deposition. The ZrOx film compositions were analyzed using x-ray photoelectron spectroscopy and density functional theory simulations. The multiple resistive switching phenomenon in TaN/ZrOx/Ni memristors was found to occur in a certain range of x ≥ 1.78. With the x value decreasing in the oxide layers, the forming voltage of memristors decreased. Furthermore, at the lower edge of x values the switchable range, they no longer required forming. At the same time, as the x value decreased, the memory window (ION/IOFF ratio) also decreased from 5 to 1 order of magnitude due to an increase in the memristor conductivity in the high resistance state. In order to identify the underlying conduction mechanism of TaN/ZrOx/Ni memristors, their current-voltage curves in low and high resistance states were analyzed in the temperature range from 250 to 400 K for the samples with x = 1.78 (forming-free) and 1.97 (which required forming). It was found that, for both samples, the conductivity in the low-resistance state is characterized by the trap-free space-charge-limited current (SCLC) model, whereas the conductivity in the high-resistance state is characterized by the trap-mediated SCLC model. The possible origins of structural defects involved in the memristor conductivity and resistive switching are discussed based on the obtained results.
•CDSD-296 is aimed at atmospheric applications.•CDSD-296 contains data of all 12 stable CO2 isotopologues.•CDSD-296 is based on global fits of measured line positions and intensities.•CDSD-296 ...broadening and shifting data are based on the Gamache and Hartmann model.•CDSD-296 contains calculated line parameters for the 345 – 14,075 cm−1 spectral range.
In 2015 we published an atmospheric version, CDSD-296, of the carbon dioxide spectroscopic databank (CDSD) Tashkun et al., JQSRT 152 (2015) 45–73. Since that time many new experimental data have been published. Some CDSD data deficiencies have also been found. The purpose of the present work is to present a corrected and extended version of the databank. In particular, it includes more realistic uncertainties of the line positions and intensities. The databank contains the calculated line parameters (positions, intensities, air- and self-broadened half-widths and their coefficients of temperature dependence, as well as air- and self- pressure-induced shifts) of the twelve stable isotopic species of CO2. The reference temperature is 296 K, and the intensity cutoff is 10−30 cm−1/(molecule cm−2). More than 530,000 lines covering the 345–14,076 cm−1 spectral range are included in the databank. Comparisons of the new version of the CDSD with UCL, AMES and HITRAN2016 line lists are also given.
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