Zhou Y, Feng Y, Lu H
Department of Physics, Nanjing Normal University, 210097 Nanjing.
Guang Pu Xue Yu Guang Pu Fen Xi. 2000 Feb;20(1):23-4.
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 spectrum. 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.
