Calcium Fluoride (CaF2)

Bezuidenhout, Dirk F.

doi:10.1016/b978-0-08-055630-7.50051-1

Cited by 5 publications

(4 citation statements)

References 62 publications

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“…To compute the IMFP, optical data such as scattering factors, f 1 and f 2 , refractive index n , and extinction index k have been collected from the literature. − Table displays the data used to compute the ELF and the available parameters according to the published data.…”

Section: Energy-loss Functions (Elf)mentioning

confidence: 99%

Electron Inelastic Mean Free Paths for LiF, CaF₂, Al₂O₃, and Liquid Water from 433 keV down to the Energy Gap

Villarrubia

Massillon‐JL

2020

ACS Omega

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We report new calculations, which include the influence of the band gap and exciton states, of the electron inelastic mean free path (IMFP) for liquid water, LiF, CaF 2 , and Al 2 O 3 from the band gap to 433 keV. Among compounds, liquid water is the most studied due to its role in radiobiological research, whereas LiF and CaF 2 are the most widely used thermoluminescent dosimeters in environmental monitoring and medical and space dosimetry. Due to its sensitivity, the optically stimulated luminescent dosimeter, Al 2 O 3 , has recently begun to be used for personnel monitoring. Previous treatments have modified the integration domain to consider the indistinguishability between the incident electron and the ejected one or the bandgap energy for nonconductors but not to accommodate exciton states within the band gap, and no published IMFP data are available for CaF 2 . Our calculation was carried out using an electron-beam−solid-state interaction model through the relativistic full Penn algorithm. Integration limits that consider the band gap, the valence band width, and exciton interactions have been used. The results suggest that, at electron energies below 100 eV, the different choices of models for integration limits and the exciton interaction can affect the IMFP by 9−29%. At higher energies, the differences associated with the choice of energy-loss function and other input parameters are around 2.5−7.5%.

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Section: Energy-loss Functions (Elf)mentioning

confidence: 99%

Electron Inelastic Mean Free Paths for LiF, CaF₂, Al₂O₃, and Liquid Water from 433 keV down to the Energy Gap

Villarrubia

Massillon‐JL

2020

ACS Omega

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“…For consistency of the fittings with other known criteria, we have selected fittings for which the extrapolation at zero frequency of the dielectric constant ε 0 is in agreement with the one known in the literature at ambient temperature (i.e. 6.63 for CaF 2 [9], 6.7-7.4 for BaF 2 [11] and 9.395 for Al 2 O 3 ordinary ray [18]). We also have tried to impose as much as possible that parameters appearing in the dielectric constants and in the self-energy (see tables 1-3 and figures 4-9) evolve linearly with temperature.…”

Section: Fitting Results and Discussionmentioning

confidence: 99%

“…Additionally, we also perform measurements on sapphire (Al 2 O 3 , perpendicular c axis), a well-known optical window material that is considered as a reference for the optical properties and for the planned experiments. To the best of our knowledge, the literature results concerning CaF 2 are limited to ambient temperature [7][8][9] and 100 K [8] range. For BaF 2 [7,10,11], reflectance data were given for the following temperatures: 295, 373, 573 and 773 K. Large discrepancies between published results and their low resolution justify the realization of new measurements.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of the dielectric permittivity of CaF₂, BaF₂and Al₂O₃: application to the prediction of a temperature-dependent van der Waals surface interaction exerted onto a neighbouring Cs(8P_3/2) atom

Silans¹,

Maurin²,

Segundo³

et al. 2009

J. Phys.: Condens. Matter

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The temperature behaviour in the range 22-500 °C of the dielectric permittivity in the infrared range is investigated for CaF(2), BaF(2) and Al(2)O(3) through reflectivity measurements. The dielectric permittivity is retrieved by fitting reflectivity spectra with a model taking into account multiphonon contributions. The results extrapolated from the measurements are applied to predict a temperature-dependent atom-surface van der Waals interaction. We specifically consider as the atom of interest Cs(8P(3/2)), the most relevant virtual couplings of which fall in the range of thermal radiation and are located in the vicinity of the reststrahlen band of fluoride materials.

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“…The computational tools are described in detail in 14,35 and references therein. The spectral RIs of the materials comprising the MM design are found in [36][37][38] .…”

Section: Methodsmentioning

confidence: 99%

Mid-infrared photodetector spectrometer concept based on ultra-thin all-dielectric metamaterial with azimuth-incidence-angle tuned perfect optical absorption: Design and analysis

Avrahamy

Zohar

Milgrom

et al. 2023

Preprint

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Novel concepts for efficient compact spectroscopy are extensively researched due to their fundamental applications in prominent fields such as biology, pharmaceutical, chemistry, physics, and environment. Here we aim to introduce such a concept with potentially unprecedented, to the best of our knowledge, resolution in the impinging radiation's spectra and azimuth. Though it can be employed in various spectral regions, we exemplify the concept in the mid-infrared, in which its advantages are paramount and have yet to be established industrially. The concept is based on the design and instrumentation of optical absorption spectral tuning (or sensitivity) to the azimuthal component of light impinging on specifically-designed metamaterials. We exemplify the concept with vacuum-wavelength (λ0) scale thick metamaterials optimized for perfect photo-absorption inside an embedded λ0/200 ultra-thin layer of lead telluride. We propose and analyze two small-footprint system designs to instrument the spectral-azimuth-angle tuning for spectrometry. The first is based on a single or few spinning metamaterial layout elements (pixels), and the second, to avoid spinning, follows a fixed focal-plane-array approach. The latter exploits the inherent variations in the local azimuthal-incidence angle instead of the typically utilized slightly varying polar angles. While low absorption is the Achilles heel of conventional mid-infrared photodetector spectrometers, the optimized pixels, in addition to their unique spectral-azimuth-angle tuning functionality, provide giant absorption enhancement, which facilitates higher resolution and even smaller in-plane form factor. The highlighted concept opens an additional dimension to encode and decode spectral information, which yields profound advantages over conventional designs as diffraction gratings based.

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Calcium Fluoride (CaF2)

Cited by 5 publications

References 62 publications

Electron Inelastic Mean Free Paths for LiF, CaF₂, Al₂O₃, and Liquid Water from 433 keV down to the Energy Gap

Electron Inelastic Mean Free Paths for LiF, CaF₂, Al₂O₃, and Liquid Water from 433 keV down to the Energy Gap

Temperature dependence of the dielectric permittivity of CaF₂, BaF₂and Al₂O₃: application to the prediction of a temperature-dependent van der Waals surface interaction exerted onto a neighbouring Cs(8P_3/2) atom

Mid-infrared photodetector spectrometer concept based on ultra-thin all-dielectric metamaterial with azimuth-incidence-angle tuned perfect optical absorption: Design and analysis

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Calcium Fluoride (CaF2)

Cited by 5 publications

References 62 publications

Electron Inelastic Mean Free Paths for LiF, CaF2, Al2O3, and Liquid Water from 433 keV down to the Energy Gap

Electron Inelastic Mean Free Paths for LiF, CaF2, Al2O3, and Liquid Water from 433 keV down to the Energy Gap

Temperature dependence of the dielectric permittivity of CaF2, BaF2and Al2O3: application to the prediction of a temperature-dependent van der Waals surface interaction exerted onto a neighbouring Cs(8P3/2) atom

Mid-infrared photodetector spectrometer concept based on ultra-thin all-dielectric metamaterial with azimuth-incidence-angle tuned perfect optical absorption: Design and analysis

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Electron Inelastic Mean Free Paths for LiF, CaF₂, Al₂O₃, and Liquid Water from 433 keV down to the Energy Gap

Electron Inelastic Mean Free Paths for LiF, CaF₂, Al₂O₃, and Liquid Water from 433 keV down to the Energy Gap

Temperature dependence of the dielectric permittivity of CaF₂, BaF₂and Al₂O₃: application to the prediction of a temperature-dependent van der Waals surface interaction exerted onto a neighbouring Cs(8P_3/2) atom