Optical Data of Cosmic Dust Analogues

Laboratory Astrophysics Group of the AIU Jena

Additional information about natural und annealed spinel:

The nonstoichiometric spinel was synthesized from magnesium carbonate and aluminium hydroxide powders. The powders have been mixed in the corresponding proportions and melted in an electric arc furnace at about 2300-2400 K. Afterwards, the melt droplets have been polished for reflection spectroscopy. Finally, the optical constants were obtained by oscillator fit analysis to the reflection spectra.
  • Reflection spectra, the dashed lines are the oscillator fits, respectively:

    By doing oscillator fit analysis, the optical constants have been derived:

    The optical constants:

  • Mg10: Mg(1.01) Al(1.99) O(4) (synthetic)
  • Mg09: Mg(0.94) Al(2.04) O(4) (synthetic)
  • Mg08: Mg(0.82) Al(2.12) O(4) (synthetic)
  • Mg07: Mg(0.73) Al(2.17) O(4) (synthetic)
  • Mg05: Mg(0.53) Al(2.31) O(4) (synthetic)
  • Mg04: Mg(0.43) Al(2.38) O(4) (synthetic)

    Using these data, mid-IR emissivity of spinel spheres in the Rayleigh limit have been calculated.

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    Last modified: J. Weiprecht Feb. 2020