J/A+A/553/A81 Refraction of corundum, spinel, α-quartz (Zeidler+, 2013)
Optical constants of refractory oxides at high temperatures.
The mid-infrared properties of corundum, spinel and α-quartz.
Zeidler S., Posch T., Mutschke H.
<Astron. Astrophys. 553, A81 (2013)>
=2013A&A...553A..81Z 2013A&A...553A..81Z
ADC_Keywords: Spectra, infrared ; Models
Keywords: circumstellar matter - infrared: stars - methods: laboratory
Abstract:
Many cosmic dust species, among them refractory oxides, form at
temperatures higher than 300K. Nevertheless, most astrophysical
studies are based on the room-temperature optical constants of solids,
such as corundum and spinel. A more realistic approach is needed for
these materials, especially in the context of modeling late-type
stars.
We aimed at deriving sets of optical constants of selected,
astrophysically relevant oxide dust species with high melting points.
A high-temperature, high-pressure cell and a Fourier-transform
spectrometer were used to measure reflectance spectra of polished
samples. For corundum (α-Al2O3), spinel (MgAl2O4), and
α-quartz (SiO2), temperature-dependent optical constants were
measured from 300K up to more than 900K. Small particle spectra were
also calculated from these data.
Description:
The files contain the optical constants (real (n) and imaginary (k)
part of the complex refractory index) which are calculated out of the
parameters of the oscillator fits to measured, polarized reflection
spectra of several minerals at high temperatures presented in the
related paper. The minerals for which reflection spectra have been
taken are corundum (α-Al2O3), spinel (MgAl2O4), and
α-quartz (SiO2). The reflection spectra and the corresponding
fits are presented in the paper.
The reflection R on a surface at near normal incidence in a vacuum can
be expressed as a function of n and k:
R=[(1-n)2+k2]/[(1+n)2+k2]
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
co300p.dat 72 1500 Optical constants of corundum at 300K, polarized
parallel to crystallographic c-axis
co300s.dat 72 1500 Optical constants of corundum at 300K, polarized
perpendicular to crystallographic c-axis
co551p.dat 72 1500 Optical constants of corundum at 551K, polarized
parallel to crystallographic c-axis
co551s.dat 72 1500 Optical constants of corundum at 551K, polarized
perpendicular to crystallographic c-axis
co738p.dat 72 1500 Optical constants of corundum at 738K, polarized
parallel to crystallographic c-axis
co738s.dat 72 1500 Optical constants of corundum at 738K, polarized
perpendicular to crystallographic c-axis
co928p.dat 72 1500 Optical constants of corundum at 928K, polarized
parallel to crystallographic c-axis
co928s.dat 72 1500 Optical constants of corundum at 928K, polarized
perpendicular to crystallographic c-axis
sp_300.dat 72 1500 Optical constants of spinel at 300K
sp_551.dat 72 1500 Optical constants of spinel at 551K
sp_738.dat 72 1500 Optical constants of spinel at 738K
sp_928.dat 72 1500 Optical constants of spinel at 928K
qu300p.dat 72 1500 Optical constants of quartz at 300K, polarized
parallel to crystallographic c-axis
qu300s.dat 72 1500 Optical constants of quartz at 300K, polarized
perpendicular to crystallographic c-axis
qu551p.dat 72 1500 Optical constants of quartz at 551K, polarized
parallel to crystallographic c-axis
qu551s.dat 72 1500 Optical constants of quartz at 551K, polarized
perpendicular to crystallographic c-axis
qu738p.dat 72 1500 Optical constants of quartz at 738K, polarized
parallel to crystallographic c-axis
qu738s.dat 72 1500 Optical constants of quartz at 738K, polarized
perpendicular to crystallographic c-axis
qu833p.dat 72 1500 Optical constants of quartz at 833K, polarized
parallel to crystallographic c-axis
qu833s.dat 72 1500 Optical constants of quartz at 833K, polarized
perpendicular to crystallographic c-axis
qu928p.dat 72 1500 Optical constants of quartz at 928K, polarized
parallel to crystallographic c-axis
qu928s.dat 72 1500 Optical constants of quartz at 928K, polarized
perpendicular to crystallographic c-axis
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See also:
J/ApJS/86/713 : IR spectroscopy of ices (Hudgins+, 1993)
J/A+A/423/983 : Meteoritic nano-diamonds optical constants (Mutschke+, 2004)
J/A+A/483/661 : Refractive index for silicon carbide (SiC) (Pitman+, 2008)
J/ApJ/701/1347 : Optical constants of H2O-ice (Mastrapa+, 2009)
J/ApJS/191/96 : IR spectra & optical constants of nitrile ices (Moore+, 2010)
Byte-by-byte Description of file: co*.dat qu*.dat sp*.dat
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Bytes Format Units Label Explanations
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1- 20 F20.14 um lambda Wavelength λ (µm)
27- 48 E22.16 --- n real part of complex refractory index
51- 72 E22.16 --- k imaginary part of complex refractory index
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Acknowledgements:
Simon Zeidler, simon.zeidler(at)uni-jena.de
(End) Patricia Vannier [CDS] 23-Apr-2013