Preparation, characterization and properties of LnSmWO$$₆$$ (Ln = Nd and Dy) nanofunctional ceramics

Isovalent substitution of lanthanide ions in (hbox {Ln}_{{2}}hbox {WO}₆ ) (Ln = lanthanides) nanoceramics can probe into multifunctional applications due to their unique structural and electronic properties. In this work (hbox {Sm}³⁺) ions in the (hbox {Sm}_{{2}}hbox {WO}_{{6}}) nanoceramics were partially replaced with (hbox {Nd}³⁺) and (hbox {Dy}³⁺) ions and their structural, optical and ionic transport properties were studied. The size and structure of the nanocrystalline (hbox {LnSmWO}_{{6}}) (Ln = Nd and Dy) compounds prepared through a combustion method were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and transmission electron microscopy (TEM). UV–Visible spectroscopy and photoluminescence spectroscopy were used for the investigation of optical and electronic properties of the nanoceramics. Bulk ceramics prepared from the nanoparticles achieved high-density during the sintering process and the surface morphology of the dense (hbox {NdSmWO}_{{6}}) was imaged using scanning electron microscopy. The electrical properties of the dense ceramics were analysed using impedance spectroscopy. XRD analysis carried out on the prepared materials showed a single-phase monoclinic structure for the nanoceramics. A combined analysis of FTIR and Raman studies showed the presence of Ln–O and O–W–O vibrations, which confirm the monoclinic structure. Particulate properties investigated through the TEM imaging showed that the prepared materials are polycrystalline aggregates. Optical studies carried out on the nanoparticles showed absorption in the UV region and emission in the visible region. Impedance spectroscopic studies conducted on bulk ceramics imply that these are good oxide ion conductors at high-temperature.