Chalcogenide glasses with Ge10AsxTe90−x (x = 20, 25, 30, 35,
40, 45 and 55 at.%) were prepared by melt quenching technique. The glass
transition temperature, the crystallization temperature, the melting
temperature and the glass-forming tendency were determined from the
differential scanning calorimetry measurements. The structural and optical
properties of Ge10AsxTe90−x thin films prepared by electron
beam evaporation were studied. X-ray diffraction showed that the
as-evaporated films are amorphous and crystallize after annealing depending
on the As content. The transmittance and reflectance of the films are found
to be thickness dependent. The optical-absorption data indicate that the
absorption mechanism is direct transition. The optical band gap values are
increased with increasing As content while they decrease with increasing the
film thickness. Upon annealing the transmittance and the optical band gap
decrease whereas the reflectance and the refractive index increase.