Structural, optical, and magnetic properties of NiMoO4 nanorods prepared by microwave sintering.

We report on the structural, optical, and magnetic properties of α,ß-NiMoO4 nanorods synthesized by annealing the NiMoO4:nH2O precursor at 600°C for 10 minutes in a domestic microwave. The crystalline structure properties of α,ß-NiMoO4 were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Raman (FT-Raman) spectroscopies. The particle morphologies and size distributions were identified by field emission microscopy (FE-SEM). Experimental data were obtained by magnetization measurements for different applied magnetic fields. Optical properties were analyzed by ultraviolet-visible (UV-vis) and photoluminescence (PL) measurements. Our results revealed that the oxygen atoms occupy different positions and are very disturbed in the lattice and exhibit a particular characteristic related to differences in the length of the chemical bonds (Ni-O and Mo-O) of the cluster structure or defect densities in the crystalline α,ß-NiMoO4 nanorods, which are the key to a deeper understanding of the exploitable physical and chemical properties in this study.

Identifying and rationalizing the morphological, structural, and optical properties of [Formula: see text]-Ag2MoO4 microcrystals, and the formation process of Ag nanoparticles on their surfaces: combining experimental data and first-principles calculations.

We present a combined theoretical and experimental study on the morphological, structural, and optical properties of ß-Ag2MoO4 microcrystals. ß-Ag2MoO4 samples were prepared by a co-precipitation method. The nucleation and formation of Ag nanoparticles on ß-Ag2MoO4 during electron beam irradiation were also analyzed as a function of electron beam dose. These events were directly monitored in real-time using in situ field emission scanning electron microscopy (FE-SEM). The thermodynamic equilibrium shape of the ß-Ag2MoO4 crystals was built with low-index surfaces (001), (011), and (111) through a Wulff construction. This shape suggests that the (011) face is the dominating surface in the ideal morphology. A significant increase in the values of the surface energy for the (011) face versus those of the other surfaces was observed, which allowed us to find agreement between the experimental and theoretical morphologies. Our investigation of the different morphologies and structures of the ß-Ag2MoO4 crystals provided insight into how the crystal morphology can be controlled so that the surface chemistry of ß-Ag2MoO4 can be tuned for specific applications. The presence of structural disorder in the tetrahedral [MoO4] and octahedral [AgO6] clusters, the building blocks of ß-Ag2MoO4, was used to explain the experimentally measured optical properties.