Microwave-Assisted Synthesis of MWO_4 and MMoO_4 (M = Ca, Ni) Nano-Powders Using Citrate Complex Precursor

摘要

Nano-sized MWO_4 and MMoO_4 (M = Ca, Ni) powders, which have scheelite and wolframite type structure, were successfully synthesized at low temperatures by a modified citrate complex method assisted by microwave irradiation. The citrate complex precursors were heat-treated at temperatures from 300 to 600 deg C for 3 h. Crystallization of the MWO_4 and MMoO_4 precursors was detected at 400 deg C and completed at a temperature of 500 deg C. Most of the MWO_4 and MMoO_4 powders heat-treated between 300 and 600 deg C showed primarily spherical and homogeneous morphology. The average crystallite sizes of MWO_4 (M = Ca, Ni) were between 22 and 39 nm, and those for MMoO_4 (M = Ca, Ni) were between 19 and 35 nm respectively, showing an ordinary tendency to grow with temperature.