The gadolinium effect on crystallization behavior and luminescence of β-NaYF4:Yb,Er phase

Single phase β-NaY0.8-xGdxYb0.18Er0.02F4 nanoparticles with different concentrations of gadolinium ions were prepared via PVP-assisted solvothermal treating at 200°C (PVP- polyvinylpyrrolidone). With the increase in Gd3+ concentration, size of the nanoparticles decreased. The up-converting spectra recorded upon 980 nm irradiation showed the green (510-560 nm) and red (640-690 nm) emissions, due to 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively. The strongest up-conversion luminescence was detected in 15 mol% Gd3+-doped nanoparticles obtained after 20 hours of solvothermal treating. With the rise of Gd3+ content up-conversion emission decreased due to increased defect concentration in the NaYF4 matrix. Fourier transform infrared spectroscopy proved in situ generation of hydrophilic nanoparticles as a result of PVP ligands retention at the particle surface.This is the peer-reviewed version of the article: Vuković Marina, Mančić Lidija, Dinić Ivana, Vulić Predrag, Nikolić Marko G., Tan Zhenquan, Milošević Olivera, "The gadolinium effect on crystallization behavior and luminescence of β-NaYF4:Yb,Er phase" International Journal of Applied Ceramic Technology, 17, no. 3 (2020):1445-1452, [https://doi.org/10.1111/ijac.13363]Published version: [https://hdl.handle.net/21.15107/rcub_dais_8947

Influence of Gd3+ doping on the NaYF4 :YB3+,ER3+ structural and up-conversion properties

application as lasers, displays, photo-thermal agents and biomarkers. Due to efficient two-phonon excitation and the large anti-Stocks shift UCNPs are able to emit visible or UV photons under excitation by near-infrared (NIR). Over the last decade, decomposition of organometallic compounds has been indicated as one of the most convenient method for the synthesis of monodisperse NaYF4:Yb3+,Er3+ UCNPs with a hexagonal crystal structure. Herein, NaY0.8-xGdxYb0.18Er0.02F4 (x= 0.3 or 0.15) up-conversion nanoparticles crystallized in the hexagonal space group P63/m were successfully synthesized solvothermally utilizing rare earth nitrates, NaF and polyvinylpyrrolidone (PVP) in ethanol-water mixture at 200 °C. Rietveld refinement of the X-ray powder diffraction (XRPD) data and high resolution transmission microscopy (HRTEM) analysis show that all UCNPs are monocrystalline (60-70 nm), have low defect concentration and uniform dopants distribution. Fourier-transform infrared (FTIR) spectroscopy indicate existence of the PVP ligands at the UCNPs surface, while photoluminescence (PL) spectra shows characteristic green (at 520 and 540 nm, due to 2H11/2, 4S3/2→4I15/2 transitions) and red (at 655 nm, due to 4F9/2 → 4I15/2 transition) emission lines under excitation by NIR (λ =980 nm) light

Titanium peroxide nanoparticles enhanced cytotoxic effects of X-ray irradiation against pancreatic cancer model through reactive oxygen species generation in vitro and in vivo

Details of the synthetic protocol for PAA-TiOxNPs formation from TiO2NPs. (PPTX 151 kb

Polymer Microstructures Self-Assemble on Single-Walled Carbon Nanotube Thin Films

The formation of self-assembled microstructures of anionic polyelectrolyte, poly­(acrylic acid) salts, on the surface of single-walled carbon nanotube thin films was studied by a fast phase separation process that filtrated a mixed dispersion composed of single-walled carbon nanotubes and poly­(acrylic acid) derivatives on a membrane filter. The resulting microstructures of poly­(acrylic acid) self-assembly were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, element mapping, and diffuse reflectance Fourier transform infrared spectroscopy. The influence factors including substrate, ion species, single-walled carbon nanotubes, and different kinds of carbon nanotubes were discussed comprehensively for the formation of microstructures of PAA self-assembly by a liquid–liquid phase separation