Emission Spectra Of Sm3 Research Articles

Optical Transition Probability of Sm 3+ Ions in aPolymer Optical Fibre

We investigate optical absorption and emission spectra of Sm 3+ ions in Sm(DBM)3Phen-doped polymethyl methacrylate (PMMA). Basedon the Judd–Ofelt theory, the optical intensity parameters arecalculated to be Ω2 = 13.76×10−20 cm2,Ω4 = 3.41×10−20 cm2, Ω6 = 4.01×10−20 cm2 from the absorption spectrum ofSm(DBM)3Phen-doped polymethyl methacrylate. The opticalintensity parameters have been used to calculate the total radiativetransition rate (676.57 s −1 ) and radiative lifetime (1478 μs) ofthe 4 G 5/2 exciting state. The stimulated emissioncross-sections σ ij and the fluorescence branch ratios forthe 4 G 5/2→6 F J′ and 4 G 5/2→6 H J′ transitions are alsoevaluated. The analysis reveals that Sm(DBM)3Phen-doped PMMA ispromising for applications in rare-earth-doped polymer devices.

Luminescence properties of Sm 2+-activated barium chloroborates

The luminescence properties of Sm 2+-activated stoichiometric and non-stoichiometric Ba 2B 5O 9Cl were investigated from 16 to 450 K. In stoichiometric Ba 2B 5O 9Cl, the emission spectra of Sm 2+ are composed of 4f 6→4f 6 transitions over the 16–450 K temperature range studied. Luminescence was observed from Sm 2+ in four inequivalent cationic sites at 16 K and two inequivalent sites at room temperature. In the non-stoichiometric compound, the emission is characterized by 4f 6→4f 6 transitions at low temperature and 4f 55d 1→4f 6 transitions at high temperature. The Sm 2+ doped into the Ca 2+ and Sr 2+ analogues in the M 2B 5O 9Cl series shows the broad band 4f 55d 1→4f 6 luminescence in both the stoichiometric and non-stoichiometric compounds due to the increased ligand field caused by the smaller ionic radii of the metal ions.

Energy transfer luminescence of Tb3+ ion complexed with calix[4]arenetetrasulfonate and the thia and sulfonyl analogue. The effect of bridging groupsElectronic supplementary information (ESI) available: emission spectra of Sm3+ and Dy3+ ions complexed with 2; emission spectra of Sm3+, Eu3+ and Dy3+ complexed with 3; continuous variation curves for the Tb3+ complexes with 2 and 3. See http://www.rsc.org/suppdata/p2/b0/b009151k/

New analogues of calix[4]arenetetrasulfonate (1) were prepared, in which the methylene bridges are replaced by S (2) and SO2 (3). The complexation ability of these calixarene ligands 1–3 toward Tb3+ ion and luminescence properties of the resulting complexes were examined. All the ligands formed complexes with lanthanide ions (Pr3+, Sm3+, Eu3+, Tb3+ and Dy3+), among which the Tb3+ complex exhibited strong energy transfer luminescence. The pH dependence of the luminescence intensity suggested that the analogues 2 and 3 possess higher complexation ability towards Tb3+ than the parent 1, which should be ascribed to the higher acidity of the phenolic OH groups as well as the coordinating ability of the bridging groups S and SO2. The composition of the complexes of 2 and 3 was determined to be Tb3+·2 and Tb3+·3 by a molar ratio method. The photophysical properties such as emission lifetimes (τ) and quantum yields (Φ) of the complexes were estimated. Both Tb3+·2 and Tb3+·3 gave comparable τ values (0.7 ms), which are larger than that of Tb3+·(1)2 (0.6 ms). Comparison of their lifetimes in D2O solution suggested that Tb3+·2 and Tb3+·3 have four to five coordinated water molecules responsible for quenching. On the other hand, complex Tb3+·2 gave the largest Φ value (0.15), whereas Tb3+·(1)2 and Tb3+·3 gave very close Φ values (0.12 and 0.13, respectively). The results of this study showed that thiacalix[4]arenetetrasulfonate 2 and the sulfonyl analogue 3 are promising candidates for the scaffold to construct luminescence devices from the viewpoint of the higher complexation ability and luminescent performance.

Excited states of Sm 2+ in chloride host lattices

Emission spectra of Sm 2+ at different temperatures in several chloride host lattices after excitation into the 4f 55d 1 levels are presented and compared. SrZnCl 4 : Sm 2+ shows broad 4f 55d 1→4f 6 emission at room temperature while additional 5D 0→ 7F J emission is observed at lower temperatures. 4f 55d 1→4f 6 as well as 5D 0→ 7F J emission is observed in BaZnCl 4-I : Sm 2+ at room temperature, investigations at lower temperatures show only 5D 0→ 7F J emission. In spite of the very similar [BaCl 8] polyhedra in the crystal structures of BaZnCl 4-I and BaZnCl 4-II, the maximum of the 4f 55d 1→4f 6 transition at room temperature is shifted to about 400 cm −1 in BaZnCl 4-II. Again, 5D 0→ 7F J emission is observed in addition. At lower temperatures, the 5D 1→ 7F J emission is only detected. Finally, NaBaLaCl 6 : Sm 2+ shows only f→f transitions: 5D 0→ 7F J at room temperature and 5D 1→ 7F J at lower temperatures.

Spectroscopic studies of rare earth ions in MgSiO 3 gel-derived crystals

The spectroscopic properties of Eu 3+, Tb 3+, Sm 3+, Dy 3+ and Er 3+ ions in MgSiO 3 gel and the MgSiO 3 gel-derived crystals have been investigated. The main excitation band of Eu 3+ ions and Tb 3+ ions in the gel-derived crystal is attributed to a charge transfer transition and 4f–5d transition, respectively. The emission bands of Tb 3+ ions in the gel appear at the same positions as in the gel-derived crystal and the relative intensities of the groups of bands are approximately the same. Similar to Eu 3+ ions, however, the intensities of emission bands of Tb 3+ ions in the gel-derived crystal are orders of magnitude greater than that in the gel since multiphonon relaxation effectively competes with radiative transitions due to the higher phonon energy in the gel. The energy level split caused by crystal field is observed clearly in the emission spectra of Eu 3+ and Sm 3+ ion activated gel-derived crystals. The excitation and emission spectra of Sm 3+ and Dy 3+ ions in the gel-derived crystal are predominantly different from that in the gel. In contrast, the excitation and emission spectra of Er 3+ ions in gel-derived crystal are approximately the same as that in the gel with respect to the positions, numbers and intensities of excitation and emission bands.

Soft-x-ray-excited soft-x-ray appearance-potential spectra of Sm and SmB6 in the Sm 3d electron excitation region.

The resonant process previously proposed in electron-excited Sm M 4,5 emission spectra of Sm and SmB 6 was confirmed by a study of soft-x-ray-excited soft-x-ray appearance-potential spectra (XXAPS). Two peaks were observed in the XXAPS at photon energies equal to energies of the prominent peaks in the Sm M 4,5 absorption spectra. These peaks are attributed to the resonant process 3d 10 4f n ↔3d n+1 where n is the number of 4f electrons in the ground state