Impact of rare earth (La3+) doping on structural, morphological, optical and dielectric properties of NdVO4 nanoparticles

The present work reports the synthesis of LaxNd1-xVO4 where x = 0, 0.05, 0.10 and 0.15 by a solution based co-precipitation method at pH = 12 calcined at 650 degrees C in nanoparticle form. The novelty of the present work is preparation and various applications of targeted materials by using a traditional liquid-based technique at room temperature without use of any surfactants. The structural, morphological, optical and luminescent properties of as-obtained compositions were characterized by various techniques such as powder X-ray diffraction (PXRD) followed by Rietveld refinement, high-resolution transmission electron microscopy (HRTEM) with selected area electron diffraction (SAED), ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy and photoluminescence spectroscopy. The PXRD diffraction patterns confirmed tetragonal structure with crystallite size ranging between 22 and 35 nm for all four compositions. The PXRD results are further validated by Rietveld refinement method with low values of profile parameters. HRTEM supplemented with SAED analysis revealed that with a change in doping concentration, there is a change in morphology from rod-shaped to porous hexagonal-shaped features. The optical band gap values are found to be in the range of wide-band semiconductors (2-4 eV). The dielectric properties of as-prepared La-doped NdVO4 nanoparticles were investigated. The dielectric constant is low in x = 0.0 composition, whereas it increases with an increase in La3+ concentration.