Co-precipitation synthesis, characterization, thermal and spectroscopic analysis of gadolinium-doped neodymium phosphate nanoparticles

Abstract

Ultrafine particles of pure and gadolinium (Gd)-doped neodymium phosphate nanoparticles with general formulae GdxNd1−xPO4 where x = 0.00, 0.01, 0.03, 0.05 were prepared by wet chemical co-precipitation technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV) and thermogravemetric analysis (TG) were performed to characterize the samples. XRD analysis suggests that the material belongs to the monoclinic crystal system. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) studies depict that all the as-synthesized samples show spherical morphology with the formation of slight clusters. The energy-dispersive X-ray analysis (EDAX) gives elemental composition present in the grown material. FTIR analysis determines the presence of various atomic bonds within a molecule, and the present study depicts the presence of water molecule along with the phosphate group and a slight shift in wave number with doping. Thermogravemetric analysis (TG) suggests that the structural phase transition takes place above 800 °C. Raman spectra give insight into the order–disorder in the system and show relevant peaks for symmetric and antisymmetric of PO 4 3 , O–P–O bending mode, rare earth–oxygen vibrations. UV spectroscopy depicts that various absorption bands fall in the ultraviolet range and the absorption edge shifts toward the lower wavelength side (blue shift) with increase in dopant concentration.