Microwave-assisted synthesis and characterization of SrMoO4 and SrWO4 nanocrystals

Abstract

SrMoO4 and SrWO4 nanocrystals have been synthesized using Sr(NO3)2 and Na2MeO4 (Me = Mo and W) in ethylene glycol by a microwave irradiation method at 50% of 180 W for 20 min. The product phases were detected using X-ray and selected area electron diffractions. They show the body-centered primitive tetragonal structure with the lattice parameters of a = b = 5.4007 A and c = 12.0330 A for SrMoO4, and a = b = 5.4274 A and c = 11.9241 A for SrWO4. X-ray diffraction patterns of the products, obtained by simulation using CaRIne version 3.1 program, are in accordance with those of the corresponding experiment and International Centre for Diffraction Data. A transmission electron microscope revealed the presence of nanocrystals composing the products, with their sizes in the ranges of 14–40 and 14–38 nm for SrMoO4 and SrWO4, respectively. Six different vibrations of ν 1(A g), ν 3(B g), ν 3(E g), ν 4(B g), ν 2(A g), and ν f.r.(A g) were detected using a Raman spectrometer, and the ν 3(F 2) antisymmetric stretching and ν 4(F 2) bending modes of [MeO4]2− tetrahedrons using a Fourier transform infrared spectrometer. Photoluminescence emissions of SrMoO4 and SrWO4, caused by the 1 T 2 → 1 A 1 transition of electrons, were detected at 410 and 418 nm, respectively.