Ultrafine copper powder was prepared from slurry with hydrazine, a reductant, under . The influence of various reaction parameters such as temperature, reaction time, molar ratio of , PvP and NaOH to Cu in aqueous solution had been studied on the morphology and powder phase of Cu powders obtained. The production ratio of Cu from CuO was increased with the ratio of and the temperature. When the ratio of was higher than 2.5 and the temperature was higher than , CuO was completely reduced into Cu within 40 min. The crystalline size of Cu obtained became fine as the temperature increase, whereas the aggregation degree of particles was increased with the reaction time. The morphology of Cu powder depended on that of the precursor of CuO and processing conditions. The average particle size was about

Monodispersed flaky silver powder was obtained by controlling the ratios of and Agin in a mixed solution of ethylene glycol and ammonia with an addition of PVP. The effects of on its morphology and size were investigated. In molar ratio was found to be an important reaction factor for the nucleation and crystal growth of Ag powder. The synthesis of flaky powder was optimized at over 6 of molar ratio increased, the size of precipitates was increased regardless of the amount of Pt. In the absence of , the morphology and size of reduced Ag powder were found to be irregular in shape in diameter. However, homogenized fine Ag powder was obtained due to heterogeneous nucleation when used as a cat-alyst, and flaky one was synthesized with the addition of Pt over of Pt/Ag.