Absorption and Reflection Above Eg

The influence of film thickness d (0.01 to 1 im) on the absorption spectrum at 300 K in the range 2 to 5.75 eV at normal incidence was studied by Ferre [43] using the optical constants from [34]. Spectra of films with d 0.03 xm differ remarkably from those for thicker films, see a figure in paper [43]. 

The absorption peak Ei of evaporated films studied in transmission exhibits the small red shift between 300 and 60 K and in addition a reduction in half-width. But in the ferromagnetic state at 4.2 K and H = 9 kOe, three peaks are observed with right circularly polarized light P at 2.1 eV, Pi at 2.5 eV, and P at 2.75 eV. The splitting between Pi and P persists at 20 K and above. With left polarized light at 4.2 K and H = 9kOe the (only) two peaks Pi and P lie symmetrically about the position of the unsplit peak present at 20 K, Guntherodt et al. [44]. 

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