E nanoscale, as was also denoted e.g., for CeO2 [55,56], BaF2 [57], or PtNanomaterials 2022, 12,8 ofTable 2. Cont. Lattice Parameter [ Sample LaF3 () Sol-Gel Sample a0 = 7.139(six) c0 = 7.311(5) a0 = 7.077(2) c0 = 7.242(9) Crystallite Size [nm] Scherrer 12.6 0.1 11.9 0.1 Williamson all 9.8 0.1 9.0 0.1 Lattice Strain [ ] 0.11 0.01 0.13 0.GC5 GC3.3. Optical Properties of Dy3+ -Doped Xerogels Figure 3 illustrates the excitation spectra for the series of Dy3+ -doped xerogels, registered on collecting the yellow emission at em = 570 nm. Inside the near-UV and VIS ranges, the 4f9 -4f9 intra-configurational transitions originating in the six H15/2 ground state of Dy3+ ions towards the different excited levels had been noted, appropriately labeled as the six P3/2 (326 nm), four I9/2 (340 nm), six P7/2 (352 nm), four I11/2 (366 nm), four F7/2 (388 nm), 6 G11/2 (427 nm), 4I four 15/2 (452 nm), too as F9/2 (474 nm). It may be observed that the intensities of individual excitation bands have grown with decreasing La3+ :Dy3+ molar ratio because the content material of Dy3+ ions elevated. However, since the intensities of excitation bands for XG5 and XG6 samples are comparable, it may very well be stated that the energy transfer processes among Dy3+ ions began to take place, suggesting the concentration quenching. The emission spectra of Dy3+ -doped xerogels are presented in Figure 4. The spectra had been recorded upon excitation at ex = 352 nm and show three luminescence bands at 477, 570, and 655 nm, in accordance with the following transitions: four F9/2 6 H15/2 (blue), four F9/2 6 H13/2 (yellow), and four F9/2 six H11/2 (red), as was also presented in the energy level scheme in Figure 5. For fabricated xerogels, the intensities of recorded bands enhanced with decreasing in of 21 La3+ :Dy3+ molar ratio from XG1 to XG5 sample, but for XG6 (together with the highest9content of Dy3+ ) the luminescence started to quench, suggesting the occurrence in the power transfer (ET) approach between neighboring Dy3+ ions in the host.Nanomaterials 2022, 12,Figure 3. Photoluminescence excitation spectra (PLE) recorded for the series fabricated xerogels Figure three. Photoluminescence excitation spectra (PLE) recorded for the series of of fabricated xerogels by by monitoring the yellow emission atem = 570 nm. monitoring the yellow emission at em 570 nm.Nanomaterials 2022, 12,Figure 3. Photoluminescence excitation spectra (PLE) recorded for the series of fabricated xerogels 9 of 21 by monitoring the yellow emission at em = 570 nm.Nanomaterials 2022, 12,10 ofFigure four. The photoluminescence emission (PL) spectra recorded for the series of prepared xerogels upon near-UV excitation at em = 352 nm. excitation at em = 352 nm.Figure five. The energy scheme of Dy3+ Dy3+ with together with the cross-relaxation (CR) channels. Figure 5. The power level level scheme of along alongthe cross-relaxation (CR) channels.Germacrone supplier six Typically, the relative intensities in the four H15/2 (J = 3, forbidden transition) and Typically, the relative intensities from the 4F9/2 F69/2 H15/2 (J = 3, forbidden transition) 4F 6H as well as the 13/2 emissions (J = 2, hypersensitive electric ipole transition) will be the 4F9/2 6H13/29/2 emissions (J = two, hypersensitive electric ipole transition) are influenced influenced by the symmetry in the nearest framework about Dy3+ ions [59].Mosedipimod Purity & Documentation According to by the symmetry within the nearest framework around Dy3+ ions [59].PMID:23849184 Depending on recorded specrecorded spectra, yellow-to-blue (Y/B) ratios had been calculated, along with the obtained values were tra, yellow-to-blue (Y/B) r.