J/A+A/483/661ivo://CDS.VizieR/J/A+A/483/661doi:10.26093/cds/vizier.34830661CDSPitman K.M.Hofmeister A. M.Corman A.B.Speck A.K.2008-06-29T15:01:53Z2008-06-29T14:58:46ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frinfrared-astronomyspectroscopyastronomical-modelsThe 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 ({beta}) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for {beta}- and {alpha}-SiC derived from single-crystal reflectance spectra and investigate quantitatively (i) whether there is any difference between {alpha}- and {beta}-SiC that can be seen in infrared (IR) spectra and optical functions and (ii) whether weak features from {lambda}~12.5-13.0{mu}m need to be fitted. We measured mid- and far-IR reflectance spectra for two samples of 3C ({beta}-)SiC and four samples of 6H ({alpha}-)SiC. For the latter group, we acquired polarized data (E{perpendicular.to}c, E{parallel.to}c orientations). We calculated the real and imaginary parts of the complex refractive index (n({lambda})+ik({lambda})) and the ideal absorption coefficients via classical dispersion fits to our reflectance spectra.2008A&A...483..661Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/483/661CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/483/661https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/483/661http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/483/661https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/483/661https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/483/661http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/483/661GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/A+A/483/661/betasicOptical constants for 3C-SiC chemical vapor deposited (CVD) wafer (table 3)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wldoublenReal part of complex refractive indexphys.refractIndexdoublekImaginary part of complex refractive indexphys.refractIndexdoubleJ/A+A/483/661/grysicpaOptical constants for gray 6H-SiC powder, extraordinary ray (table 4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wldoublenReal part of complex refractive indexphys.refractIndexdoublekImaginary part of complex refractive indexphys.refractIndexdoubleJ/A+A/483/661/grysicpeOptical constants for gray 6H-SiC powder, ordinary ray (table 5)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wldoublenReal part of complex refractive indexphys.refractIndexdoublekImaginary part of complex refractive indexphys.refractIndexdoubleJ/A+A/483/661/moisicpaOptical constants for moissanite gem, extraordinary ray (table 6 )recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wldoublenReal part of complex refractive indexphys.refractIndexdoublekImaginary part of complex refractive indexphys.refractIndexdoubleJ/A+A/483/661/moisicpeOptical constants for moissanite gem, ordinary ray (table 7)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wldoublenReal part of complex refractive indexphys.refractIndexdoublekImaginary part of complex refractive indexphys.refractIndexdouble