Optical properties of some photochromic glasses doped with transition metal oxides

Abstract

Glass is a magical material which has so many different properties and uses.Glass is melted at a temperature between 1000 and 2000° C. The microscopic structure of glass is comparable to that of a liquid in which the individual constituents form an irregular network without a long range order.Glass samples are prepared using melt quench technique. Glass batches are introduced in platinum 2% Rhodium crucibles. Glass batches are placed in an electrical furnace of temperature 1400 ℃ for time duration two hours. After melting, the prepared glasses are molded on a heated stainless steel molds and immediately placed in a muffle furnace at the appropriate temperature 450℃ for a period of two hours to achieve good annealing. Glass samples are placed in a heat treatment furnace for time duration two hours to reach photochromic. Three glass systems have been prepared. The first glass system has the composition 〖"(" 〖"SiO" 〗_"2" ")" 〗_"45" 〖"(" "B" _"2" "O" _"3" ")" 〗_"35" 〖"(" 〖"Al" 〗_"2" "O" _"3" ")" 〗_"7.5" (〖"Na" 〗_"2" "O" )_"12.5" doped with(AgBr)_0.6 (〖Cu〗_2 O)_0.04 (TiO_2 )_x with x=0,1,2,4 and 6 g The second glass system has the composition 〖"(" 〖"SiO" 〗_"2" ")" 〗_"45" 〖"(" "B" _"2" "O" _"3" ")" 〗_"35" 〖"(" 〖"Al" 〗_"2" "O" _"3" ")" 〗_"7.5" (〖"Na" 〗_"2" "O" )_"12.5" doped with(AgBr)_0.6 (〖Cu〗_2 O)_0.04 (CoO)_x with x=0,0.006,0.02and 0.07 g The third glass system has the composition 〖"(" 〖"SiO" 〗_"2" ")" 〗_"45" 〖"(" "B" _"2" "O" _"3" ")" 〗_"35" 〖"(" 〖"Al" 〗_"2" "O" _"3" ")" 〗_"7.5" (〖"Na" 〗_"2" "O" )_"12.5" doped with(AgBr)_0.6 (〖Cu〗_2 O)_0.04 (〖Cr〗_2 O_3 )_x with x=0,0.02 and 0.08 g The amorphous nature of these glasses is examined by X-ray diffraction analysis. Densities of the prepared samples are measured and compared with theoretical one. The densities of the first glass system are ranged between2.287-2.387 g/〖cm〗^3, 2.275-2.287 g/〖cm〗^3 for the second first glass system and 2.280-2.287 g/〖cm〗^3 for the third glass system. The absorption measurements in the Infrared region of the spectrum are recorded in the wavenumber range(4000-400)〖cm〗^(-1) for the three glass systems. Spectral reflectance and transmittance at normal incidence of the three glass systems are recorded with a double beam spectrophotometer in the spectral range200-2500 nm. Analytical expressions are used to deduce the real and imaginary parts of the refractive indices. Dispersion parameters such as: single oscillator energy, dispersion energy and Abbe's number are deduced and compared. Absorption dispersion parameters such as: optical energy gap for direct and indirect transitions, Urbach energy and steepness parameter are extracted. Predicted nonlinear optical parameters as nonlinear refractive index, nonlinear refractive index coefficient and nonlinear susceptibility are investigated and compared for the three glass systems. Effects of doping with (AgBr)(〖Cu〗_2 O)on the linear and the predicted nonlinear optical parameters are investigated and discussed.