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J/A+A/483/661      Refractive index for silicon carbide (SiC)   (Pitman+, 2008)

Optical properties of silicon carbide for astrophysical applications. I. New laboratory infrared reflectance spectra and optical constants. Pitman K.M., Hofmeister A. M., Corman A.B., Speck A.K. <Astron. Astrophys. 483, 661 (2008)> =2008A&A...483..661P
ADC_Keywords: Spectra, infrared ; Models Keywords: methods: laboratory - stars: carbon - stars: circumstellar matter - ISM: dust, extinction Abstract: The SiC optical constants are fundamental inputs for radiative transfer (RT) models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (β) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for β- and α-SiC derived from single-crystal reflectance spectra and investigate quantitatively (i) whether there is any difference between α- and β-SiC that can be seen in infrared (IR) spectra and optical functions and (ii) whether weak features from λ∼12.5-13.0µm need to be fitted. We measured mid- and far-IR reflectance spectra for two samples of 3C (β-)SiC and four samples of 6H (α-)SiC. For the latter group, we acquired polarized data (E⊥c, E¶c orientations). We calculated the real and imaginary parts of the complex refractive index (n(λ)+ik(λ)) and the ideal absorption coefficients via classical dispersion fits to our reflectance spectra. Description: These data tables contain optical functions for alpha- and beta-polytypes of silicon carbide (SiC) for wavelengths ∼2.5-200-microns at T=18-19degC and near-normal incidence. The wavelength mesh in these tables has been regridded for use in DUSTY (Nenkova et al., 2000ASPC..196..77N). Users are welcome to contact the authors directly for copies of the high resolution (4000 wavelength point) files. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file betasic.dat 37 105 Optical constants for 3C-SiC chemical vapor deposited (CVD) wafer (table 3) grysicpa.dat 37 105 Optical constants for gray 6H-SiC powder, extraordinary ray (table 4) grysicpe.dat 37 105 Optical constants for gray 6H-SiC powder, ordinary ray (table 5) moisicpa.dat 37 105 Optical constants for moissanite gem, extraordinary ray (table 6 ) moisicpe.dat 37 105 Optical constants for moissanite gem, ordinary ray (table 7)
Byte-by-byte Description of file: *.dat
Bytes Format Units Label Explanations
1- 11 E11.6 um lambda Wavelength 13- 23 E11.7 --- n Real part of complex refractive index 25- 37 E13.6 --- k Imaginary part of complex refractive index
Acknowledgements: Karly Pitman, Karly.M.Pitman(at) Jet Propulsion Laboratory, California Inst. of Technology
(End) Karly M. Pitman [JPL, CIT], Patricia Vannier [CDS] 06-Mar-2008
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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