Structural and spectral properties of undoped and tungsten doped Zn3(PO4)2ZnO nanopowders

• Published in: The Journal of physics and chemistry of solids 2018-01, Vol.112, p.200-208
• Main Authors: Satyavathi, K., Subba Rao, M., Nagabhaskararao, Y., Cole, Sandhya
• Format: Article
• Language: English
• Subjects: Hexagonal-ZnO; Monoclinic- Zn3(PO4); Octahedral symmetry; Sol-gel method
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2017.09.004

Pure and tungsten doped Zn3(PO4)2ZnO nanopowders (NPs) are prepared using sol-gel method. It has the longest track record of used in dentistry. It is used for cementation of inlays, crowns and orthodontic appliances. The systematic investigations like X-ray Diffraction (XRD), Scanning electron microscope (SEM) with energy dispersive X-ray (EDX) spectroscope, Transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectroscopy, Optical absorption, Photoluminescence (PL) and Electron Paramagnetic Resonance (EPR) spectroscopic techniques are carried out for the prepared NPs. XRD pattern reveals that the prepared samples are in crystalline nature in which Zn3(PO4)2 corresponding to monoclinic phase and ZnO corresponding to hexagonal wurtzite phase, the average crystallite size of prepared nanopowders is in the range of 20–30 nm. The lattice strain, lattice cell parameters, unit cell volume and dislocation density of the prepared NPs are also calculated. The morphology of the prepared NPs is analyzed with SEM and TEM images. The distribution of Zn, P, O and W species in the prepared samples are identified by the chemical composition mapping through EDX. IR spectra of prepared samples exhibit the characteristic sharp absorption band peaks. The sharp absorption bands observed in the region 1200-900 cm−1 are due to complex stretching of characteristic PO43− groups. The absorption spectra exhibit a broad band around 696 nm is recognized due to 2B2g → 2B1g (dxy → dx2- y2) transition of tungsten ions. The PL spectra exhibit four emission peaks in the visible region indicating the quantum-confinement-induced photoluminescence. The CIE chromaticity diagram suggests that the prepared NPs have good color purity. The EPR spectra indicate that the W5+ ions occupy octahedral site symmetry in the host lattice. [Display omitted] •Undoped and WO3-doped Zn3(PO4)2ZnO NPs are synthesized by Sol-gel route.•The variation of WO3 content does not significantly influence the phase structure.•SEM images of the prepared samples show the formation of agglomerated NPs.•In PL spectra, the emission peaks indicate high structural and optical quality.•In EPR spectra, W5+ ions exist in an octahedral site symmetry.