Laboratory Astrophysics Group of the AIU Jena
Additional information about synthetic fayalite:
A synthetic fayalite crystal from the group of Prof. Assmuss (University of Frankfurt (Main))
grown by the scull method was spectroscopically investigated .
The scull provided small (up to 4 mm sized) nearly black fayalite single fayalite crystals.
Two crystals have been crystallographically oriented by the Laue diffraction method.
Their chemical compositions were checked by energy dispersive X-ray analysis (EDX) at a SEM to Mg1.9Fe0.1SiO4.
The optical constants were obtained by oscillator fit analysis to the
Reflection spectra and lattice modes
spectra of synthetic fayalite E||x (ASCII)
spectra of synthetic fayalite E||y (ASCII)
spectra of synthetic fayalite E||z (ASCII)
By doing oscillator fit analysis, the optical constants have been derived
Fayalite E || x (ASCII)
Fayalite E || y (ASCII)
Fayalite E || z (ASCII)
Using these data, IR absorption spectra of fayalite particles have been calculated:
2) a continuous distribution of ellipsoids, where all shapes are equally probable (CDE1)
3) a distribution of ellipsoid with a quadrativ weighting, where near spherical shapes are most probable (CDE2).
The calculations have been performed for small particles in the Rayleigh limit.
Mass absorption coefficients of fayalite spheres, CDE1 and CDE2 in vacuum (ASCII).
Mass absorption coefficients of fayalite powder (d < 1 micron, ground single crystals)
by using the PE/KBr pellet technique (ASCII).
Additionally, optical constants of fayalite
are available from the Ultraviolet to the NIR. The data have been
obtained from unpolarized measured reflection and transmission spectra of thin sections.
Optical constants of fayalite from 25000 to 1000 cm-1 (ASCII)
data main page]
Last modified: Dirk Fabian, January 2002