Nickel-SiO₂ nanocomposites with nickel content equal to 14 wt% were prepared by sol-gel method starting from ethanolic (EtOH) solutions of tetraethoxysilane (TEOS) and nickel nitrate hexahydrate. After gelation the samples were thermally treated and then reduced in hydrogen flow at selected temperatures. TEOS/EtOH/H2O molar ratios (TEH), pH and gelation temperature of the gels (T_gel) have been varied within selected ranges in order to optimize the average particle size (<D>) and their size distribution.

The amorphous/crystalline nature of the materials, the occurrence of recognizable phases, and the size and size distribution of the particles were examined by x-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal behavior was followed by thermal analysis (TGA).

Very small nickel nanoparticles with average crystal size of 3 nm with a narrow size distribution have been obtained. The preparation of the sol and the treatments of the fresh gels are possible keys to control the final product.