Chalcogenide glasses with composition Ge20Se80−_x_ Tl _x_ (_x_=10, 15, 20, 25, 35%) have been prepared by the usual melt-quenching technique. Thin films of the mentioned compositions have been prepared by the electron beam evaporation. In addition, another set taken from the composition of_X_=30 at % with different thicknesses (_d_=14.7, 30.0, 56.5, 70.0, 101.0, 180.0 nm) have been taken into consideration. ... إقراء المزيد