Study on optical properties and synthesis of nanosized GeO2-SiO2 glasses

The compound material of nm size particles GeO2-SiO2 was synthesized through hydrolysis of Si(OC2H5)(4) and GeCl4 with pH-2.A heat-treatment was carried out for samples at 100 -1 200 degrees C in air. Its optical property was determined by UV-Vis specturm. We have found that the absorption edge of spectrum shifted progressively to longer wavelengths. The quantum size effect of nanocrystals appears because crystals grow and the energy of optical band gap reduces due to the influence of temperature. By the analysis of X-ray diffraction we have observed the process in which the structure of particles changed from disorder into order,and the particles with size 5 -10 nm came into obviously as temperature increased until 1 100 degrees C.