Comparative quantum chemistry study of the F-center in lanthanum trifluoride

Chuklina, N. G.; Piskunov, Sergei; Popov, N. V.; Mysovsky, A. S.; Попов, А. И.

doi:10.1016/j.nimb.2020.04.020

Cited by 9 publications

(4 citation statements)

References 49 publications

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“…Such phenomena have often been observed when anion vacancies were created in alkali metal halides and alkali earth metal halides, such as compounds of alkali metals (Li, Na, K, Rb) and halogen (F, Cl, Br, I), , CsF, and compounds between alkali earth metals and halogen (CaF 2 , BaF 2 , SrF 2 , MgF 2 ), , which are known as F -centers. The formation of in-gap states by the creation of anion vacancies was also reported for halides of other metals including AgF 2 , LaF 3 , CeF 3 , PbF 2 , and AgCl . Therefore, the insulator-to-metal transition of simple metal halides by the formation of anion vacancies, which was thought to have occurred for CuF 2 in the present study, is a rare phenomenon and has not been reported in the past.…”

Section: Resultssupporting

confidence: 77%

Fluoride Shuttle Battery Reactions of CuF₂: Intermediate Phase for Defluorination

2022

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Fluoride shuttle batteries (FSBs) that use defluorination and fluorination of active materials are considered candidates for future batteries with high energy densities. Elucidation of the mechanisms of FSB reactions is the key to developing batteries with high performance. In this work, in situ Raman mapping and three-dimensional (3D) morphology analysis by laser scanning confocal microscopy (LSCM) during defluorination of CuF 2 microparticles in a liquid electrolyte were conducted. Defluorination proceeded through a new intermediate phase of CuF 2 with fluorine vacancies, characterized by green color and distinct Raman peaks. Results of UV−vis measurements and density functional theory (DFT) calculations indicate that electrons are doped into an unoccupied Cu 3d band above the band gap of the pristine CuF 2 when a small amount of F − is extracted, resulting in photoabsorption of the intermediate phase in a red-to-infrared region and electronic conductivity. This intermediate phase is thought to promote defluorination of CuF 2 , which is initially an electronic insulator. The insulator−metal transition due to extraction of an anion has not so far been reported for simple metal halides. The results of the unique observation of spatiotemporal changes in the distribution of the intermediate phase provide important information for the development of active materials and also solid electrolytes for FSBs.

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Section: Resultssupporting

confidence: 77%

Fluoride Shuttle Battery Reactions of CuF₂: Intermediate Phase for Defluorination

2022

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“…It was widely used in the fluoride-glass ceramic [16,17], the scintillation crystals and rare earth crystal laser materials required by high-energy physics, nuclear medical imaging and industrial CT [18][19][20], arc lamp carbon electrode for lighting and other photoelectric fields, etc. [21][22][23]. Moreover, it has a low refractive index (1.4-1.6, compared with the Ge substrate) and low price.…”

Section: Introductionmentioning

confidence: 99%

Dependence of Structural and Optical Performance of Lanthanum Fluoride Antireflective Films on O Impurities

Pan

Miao

et al. 2022

Coatings

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Lanthanum fluoride (LaF3) thin films were deposited on the Ge substrate using the molybdenum boat evaporation method. The effect of films’ oxygen impurity on the infrared optical properties has been investigated for the first time in this report. With the increase in oxygen content in the films, the F content decreases, and the O/F ratio decreases from 0.160 to 0.055. XRD patterns reveal that the presence of O impurity destroys the crystal structure integrity of the LaF3 films and leads to the intensification of infrared absorption. The average transmittance decreases from 58.1% to 52.2%, and the peak transmittance decreases from 59.9% to 54.5%. Additionally, the refractive index and extinction coefficient of LaF3 films with different oxygen content are obtained by fitting the transmittance test data. The results show that the refractive index and extinction coefficient of the films in 8–12 μm increase with the increase in oxygen content, the average refractive index increases from 1.339 to 1.478, and the extinction coefficient increases from 0.001 to 0.030. In this paper, the influence of oxygen impurity in the LaF3 film on its infrared optical properties is revealed, which lays a theoretical foundation for the development of high-performance LaF3 infrared antireflective film.

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“…Nowadays, with the tremendous revolution of computation techniques, theoretical calculations based on quantum-chemical methods have become a significant tool to in-vestigate photon-absorption mechanisms in solids. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) accompanied with the linear combination of atomic orbitals (LCAO) method allow the simulations of up to hundreds-atom structures and provide the reasonable equilibrium between accuracy, computational cost, and agreement with the experiment [16][17][18][19][20][21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Time-Dependent Density Functional Theory Calculations of N- and S-Doped TiO2 Nanotube for Water-Splitting Applications

et al. 2021

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On the basis of time-dependent density functional theory (TD-DFT) we performed first-principle calculations to predict optical properties and transition states of pristine, N- and S-doped, and N+S-codoped anatase TiO2 nanotubes of 1 nm-diameter. The host O atoms of the pristine TiO2 nanotube were substituted by N and S atoms to evaluate the influence of dopants on the photocatalytic properties of hollow titania nanostructures. The charge transition mechanism promoted by dopants positioned in the nanotube wall clearly demonstrates the constructive and destructive contributions to photoabsorption by means of calculated transition contribution maps. Based on the results of our calculations, we predict an increased visible-light-driven photoresponse in N- and S-doped and the N+S-codoped TiO2 nanotubes, enhancing the efficiency of hydrogen production in water-splitting applications.

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Comparative quantum chemistry study of the F-center in lanthanum trifluoride

Cited by 9 publications

References 49 publications

Fluoride Shuttle Battery Reactions of CuF₂: Intermediate Phase for Defluorination

Fluoride Shuttle Battery Reactions of CuF₂: Intermediate Phase for Defluorination

Dependence of Structural and Optical Performance of Lanthanum Fluoride Antireflective Films on O Impurities

Time-Dependent Density Functional Theory Calculations of N- and S-Doped TiO2 Nanotube for Water-Splitting Applications

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Comparative quantum chemistry study of the F-center in lanthanum trifluoride

Cited by 9 publications

References 49 publications

Fluoride Shuttle Battery Reactions of CuF2: Intermediate Phase for Defluorination

Fluoride Shuttle Battery Reactions of CuF2: Intermediate Phase for Defluorination

Dependence of Structural and Optical Performance of Lanthanum Fluoride Antireflective Films on O Impurities

Time-Dependent Density Functional Theory Calculations of N- and S-Doped TiO2 Nanotube for Water-Splitting Applications

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Fluoride Shuttle Battery Reactions of CuF₂: Intermediate Phase for Defluorination

Fluoride Shuttle Battery Reactions of CuF₂: Intermediate Phase for Defluorination