Synthesis and structural characterization of YVO3 prepared by sol–gel acrylamide polymerization and solid state reaction methods

Abstract

The formation of the YVO3 compound obtained by sol–gel acrylamide polymerization is reported. This synthesis method is contrasted with solid state reaction. Differential thermal analysis (DTA) results show the formation of YVO3 at 805 °C compared with 1312 °C for solid state reaction. Thermogravimetric analysis (TG) results show that between 400 and 600 °C the denaturalization of the organic part, ethylenediamine, and the decomposition of nitrates occur. The evolution of YVO4 into YVO3 was also studied by X-ray powder diffraction (XRD). The refinement results obtained for both YVO3 samples show an orthorhombic phase with Pbnm (62) space group and lattice parameters: a = 5.283 A, b = 5.605 A and c = 7.580 A. Grain size and morphology evolution for different heat treatments were studied with scanning electron microscopy (SEM). The use of sol–gel acrylamide synthesis allows us to start with a homogeneous grain distribution with a mean size of 5.03 ± 0.65 nm growing up to 4.11 ± 0.87 μm in YVO4. After reduction to YVO3 the final grain size was 2.87 ± 0.10 μm also with grain size homogeneity. This is in contrast with samples prepared by solid state reaction for which the grain size starts (YVO4) between 1 and 7.0 μm and ends (YVO3) with a size distribution centered at 90.32 ± 74.46 μm. Transmission electron microscopy (TEM) results corroborate XRD results. Energy dispersive X-ray (EDX) results are in agreement with theoretical values.