Spectral Characteristics of Mn²⁺ Doped Na₅Lu₉F₃₂ Single Crystals

Abstract

Mn 2þ ion doped Na 5 Lu 9 F 32 single crystals are grown by an improved Bridgman method. The absorption and fluorescence spectrum of single crystals in the range of 300-800 nm are measured to investigate the spectral properties. Fluorescent band centered at 550 nm was observed in the fluorescence spectrum of the crystals corresponding to the 4 T 1 ( 4 G) ! 6 A 1 ( 6 S) transition of the Mn 2þ ion. An excitation peak of 400 nm is observed in the excitation spectrum due to the charge transfer transition of electrons from the ground state to the conduction band. The calculated values for the crystal field (Dq) and Racah parameters indicate that a stable cubic crystal structure of Mn 2þ ion surrounded by eight F À ligands can be formed with the introduction of Mn 2þ ion into Na 5 Lu 9 F 32 single crystals.

Advanced Luminescence Anticounterfeiting Based on Dynamic Photoluminescence and Non-Pre-Irradiation Mechanoluminescence

“…As shown in Table S4, when the Mn 2+ ( r = 0.83 Å, CN = 6) ions replace the Zn 2+ ( r = 0.74 Å, CN = 6) sites, it results in the expansion of the lattice and the weakening of the crystal fields. On the contrary, the substitution of Mn 2+ ( r = 0.96 Å, CN = 8) for the dodecahedral Ca 2+ ( r = 1.12 Å, CN = 8) causes the shrinkage of the crystal lattice and the strengthening of the crystal field. , Accordingly, as shown in the Tanabe–Sugano diagram of Mn 2+ in Figure d, the PL emission band centered at 536 nm of the sample should be ascribed to Mn 2+ at the octahedral Zn 2+ sites and that at 676 nm should correspond to Mn 2+ at the dodecahedral Ca 2+ sites. , …”

Insights into O2 Activation via MnIIIOOH Species on Mn-Rich Biochar

“…Notably, compared with Mn-BC, MnBC-H x exhibits a blueshift from 1557 to 1606 cm –1 (Figure b), which is indicative of the increased electron density of CO of the oxalate group (−C 2 O 4 ) . Combined with a redshift in the XRD patterns at 2θ = 24.4° for monoclinic MnC 2 O 4 ·2H 2 O (Figure a, inset), it suggests Mn II of MnC 2 O 4 ·2H 2 O might be replaced by Mn III due to the smaller size of Mn III (58 pm) relative to Mn II (96 pm) . Comparatively, the blueshift in the FTIR spectra means the increase in the electron density of CO of -C 2 O 4 , which could be related to the replacement of Mn II by Mn III in the MnC 2 O 4 lattice as the introduction of Mn III would strengthen the energy of CO of -C 2 O 4 .…”

“…49 Combined with a redshift in the XRD patterns at 2θ = 24.4°for monoclinic MnC 2 O 4 •2H 2 O (Figure 2a, inset), it suggests Mn II of MnC 2 O 4 •2H 2 O might be replaced by Mn III due to the smaller size of Mn III (58 pm) relative to Mn II (96 pm). 50 Comparatively, the blueshift in the FTIR spectra means the increase in the electron density of C�O of -C 2 O 4 , 49 which could be related to the replacement of Mn II by Mn III in the MnC 2 O 4 lattice as the introduction of Mn III would strengthen the energy of C�O of -C 2 O 4 . Raman spectroscopy of MnBC-H5 indicated the formation of Mn III on the surface of MnBC-H5 by the new peak at 506 cm −1 compared to that of Mn-BC (Figure S4).…”