Synthesis of nanocrystalline MMoO4 (M = Ni, Zn) phosphors via a citrate complex route assisted by microwave irradiation and their photoluminescence

Nanocrystalline MMoO4 (M = Ni, Zn) phosphors, which have wolframite-type structure, were successfully synthesized at low temperatures via a modified citrate complex route assisted by microwave irradiation. The citrate complex precursors were heat-treated from 300 to 600 °C for 3 h. Crystallization of the MMoO4 (M = Ni, Zn) nanocrystallites were detected at 500 °C, and entirely completed at a temperature of 600 °C. The nanoparticles presented primarily dispersed and homogeneous morphology with particle size of 20–40 nm. The nanocrystalline MMoO4 (M = Ni, Zn) phosphors prepared at 600 °C exhibited broad luminescence in green and blue wavelength region, respectively.