Phase composition and photoluminescence correlations in nanocrystalline ZrO2:Eu3+ phosphors synthesized under hydrothermal conditions

Abstract

Luminescent zirconia nanoparticles with europium ion content 1 and 10 mol.% were synthesized under hydrothermal conditions. Annealing of ZrO 2 : 1 mol. Eu 3+ nanoparticles made it possible to obtain a sample with a high monoclinic phase content up to 92 %. An increase in the concentration of Eu 3+ ions introduced into the zirconia crystal lattice has made it possible to almost completely convert its monoclinic and tetragonal phases into cubic modification. The phase composition of the synthesized samples was determined by powder X-ray diffraction, electron microdiffraction, and Raman spectroscopy. Analysis of the crystallographic data and the luminescent spectra helped to reveal correlations between the ZrO 2 :Eu 3+ nanophosphor structure and the energy redistribution of Eu 3+ optical transitions at 614 -626 nm and 606 -633 nm wavelengths. In addition, a relationship was established between the phase composition of nanoparticles based on zirconia and the luminescence lifetime of Eu 3+ ions.

The use of nanocluster polyoxometalates in the bioactive substance delivery systems

“…In some cases, the factor contributing to the release of the transported drug from the nanocapsules may be the changing pH of the medium into which they find themselves. By their composition, the metal-containing biomedical nanoparticles are usually divided into purely metallic, e.g., gold copper, silver, and nanoparticles with a complex composition, for example, based on oxides of iron, copper, zinc, titanium, tungsten, on cerium and zirconium dioxides, including those containing rare earth metals [70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86], etc.…”

“…There exist various methods for producing nanoparticles [78,80,[87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102] and compositions on their basis. The most common methods for producing nanoparticles include "soft chemistry" methods, including microreactor [98][99][100] and hydrothermal [92][93][94][95][96][97] synthesis, and precipitation (sol-gel method) [87][88][89][90][91].…”

The influence of chemical prehistory on the structure, photoluminescent properties, surface and biological characteristics of Zr0.98Eu0.02O1.99 nanophosphors

“…Selectivity for the excitation wavelength, energy transfer efficiency, lifetime and quantum yield of photoluminescence are determined mainly by the structure and size of ZrO 2 crystals, as well as the concentration and localization of Ln 3+ active centers in them [26][27][28][29]. The distribution of trivalent lanthanide ions between the amorphous, monoclinic and more symmetrical tetragonal and cubic phases of ZrO 2 can be adequately distinguished using Eu3+ as a probe.…”

Structure and photoluminescent properties of TiO2:Eu3+ nanoparticles synthesized under hydro and solvothermal conditions from different precursors

“…The luminescent properties of such emitting materials depend on the efficiency of energy transfer from the absorption center (ligand) to the emission center (lanthanide ion) and on the concentration of quenchers (OH groups) surrounding photoactive ions [8]. Europium (III) ions are most often used as photoactive centers due to their intensive well-distinguishable luminescence at a wavelength of 630 nm, long luminescence lifetime and sensitivity to the symmetry of the local environment [9,10]. Luminescence of Eu 3+ ions can be effectively sensitized by the energy transfer from the excited host matrix to the photo active center as a result of allowing the 4f -4f absorption transitions by electric dipole mechanism, these transitions forbidden between the states with the same parity according to the Laporte's rule in the "pure" state (without influence of a ligand-field under non-centrosymmetric interactions) [11,12].…”