Fine structures in refractive index of sapphire at the L(II,III) absorption edge of aluminum determined by soft x-ray resonant reflectivity.

The optical constants of sapphire crystal (α-Al(2)O(3)) and amorphous Al(2)O(3) in the soft x-ray region (67-85 eV) around the aluminum L absorption edge (73.1 eV) are determined by angle-dependent x-ray reflectivity. The differences between the optical constant values of both the samples are discussed.