Synthesis of ZnWO_4 nanocrystalline powders, by the polymerized complex method

摘要

Nanocrystalline ZnWO_4 powders were successfully prepared by the polymerized complex method using zinc nitrate and tungstic acid as starting materials. The polymeric precursors were heat-treated at temperatures from 300 to 600℃ for 3h. The precursors and heat-treated powders were evaluated for crystallization process, thermal decomposition, surface morphology and crystallite size. Crystallization of the ZnWO_4 powders was detected at 400℃ and entirely completed at a temperature of 600℃. The particles heat-treated at 400 and 500℃ showed primarily co-mixed morphology with spherical and silkworm-like forms, while the particles heat-treated at 600℃ showed more homogeneous morphology with a narrow size distribution. The average crystalline sizes were 19.92-24.16nm, showing an ordinary tendency to increase with the temperatures from 400 to 600℃.