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[en] The analysis of magnetic susceptibility data related to the hydrogenation of samarium metal leads to the conclusion that the occurrence of a transition Sm3+ → Sm2+, observed in samples containing Fe as an impurity, is to be considered as a bulk effect. (Auth.)
[en] The semi-empirical realization of the Judd-Ofelt theory of f↔f transitions has proved to be a powerful tool for the reproduction of the majority of the observed lines in lanthanide doped materials. However, the theoretical description of some of the observed transitions is beyond the framework of the standard approach. In order to describe such transitions, which in particular are forbidden and hypersensitive, Smentek and Wybourne extended the standard theory by relativistic terms and introduced a new parametrization scheme of f-spectra. This parametrization scheme, which is still one-particle but based on double tensor operators, is applied here in order to reproduce the spectra observed in Nd3+ and Sm3+ in glasses. The results of numerical calculations are compared to experimental values and to those obtained within the standard Judd-Ofelt scheme as well as its version extended by the odd rank intensity parameters
[en] Highlights: • Divalent samarium is formed in air fired samples of 5%Sm:Ba2B10O17. • Minimal Sm(III) emission suggests significant reduction of the samarium ion when incorporated in 5%Sm:Ba2B10O17. • The samarium(II) emission spectrum characteristic of 5%Sm:Ba2B10O17 is reported for the first time. The samarium appears to be occupying a C2v site. - Abstract: Trivalent samarium has been found to be reduced to the divalent state during the air firing process of the preparation of 5% Sm:Ba2B10O15. This is the first time that the formation of divalent samarium has been reported as a function of the preparation of this material. The product was prepared from a co-precipitated borate which was fired at 750 °C with an additional 30% boric acid. The resulting product was confirmed by x-ray analysis and exhibited only divalent samarium emission. Based upon the observed emission, the primary samarium site can be assigned a site symmetry of C2v. The emitting samarium ion appears to occupy a tetrahedral boron site in this material.
[en] Photoluminescence spectra of ZnAl2Se4:Sm2+ due to the processes of charge carriers recombination from levels 5Dj, 5Lj, 5Gj and 5Hj (4f55d1) on levels 7Fj of samarium ions were investigated. The broad photoluminescence band at energies 1.6–1.9 eV due to optical transitions of electrons from 4f shell to 1s of samarium ions level was discovered. Emitted energy of it was absorbed by transitions from 7Fj to 5Dj levels. An up-conversion process—electron excitation from 7Fj levels to 5D0, 5D1, 5D2 levels with simultaneous electron transitions to higher energy states 5D3, 5D4, 5Lj, 5Gj, 5Hj with subsequent recombination to 7Fj levels with energy emission in short-wavelength region were found out and investigated. (paper)
[en] The magnetic moment of Sm3+ in hcp Sm was studied with a magnetic Compton-scattering experiment with the aid of a pulse magnet. We have successfully obtained direct evidence for a positive contribution of the spin moment to the total moment, opposite to the case for a free ion. The enhancement of the spin moment by incorporation of the conduction electron polarization is observed. copyright 1997 The American Physical Society
[en] In this paper we report on the Judd–Ofelt analysis of Sm3+-doped lanthanum aluminosilicate glasses. The Judd–Ofelt calculations were done using two different least-squares fitting procedures (absolute and normalized) and two different cavity models (virtual and empty cavity model). It is shown that the absolute least-squares fitting procedure for the reported glasses yields physically more reliable results for the radiative lifetimes and branching ratios of the 4G(4)5/2 emission of Sm3+ than the normalized fitting method. The Ω2 parameters decrease with increasing lanthanum concentration of the glasses indicating an effect of the glass structure (network connectivity) on hypersensitive transitions in Sm3+. For the Ω4 and Ω6 parameters a clear correlation to the glass composition was not found. - Highlights: • Judd–Ofelt analysis has been conducted on three Sm3+-doped lanthanum alumino silicate glasses. • Different frequently used fitting methods and cavity models have been used. • The two fitting methods result in completely different sets of Ω parameters. • The results of the “absolute fitting method” correspond best to experimentally derived values
[en] New polymeric membrane (PME) and coated graphite (CGE) samarium(III)-selective electrodes were prepared based on isopropyl 2-[(isopropoxycarbothioyl) disulfanyl]ethanethioate as a suitable neutral ionophore. The electrodes exhibit Nernstian slopes for Sm3+ ions over wide concentration ranges (1.0x10-5 to 1.0x10-1 M for PME and 1.0x10-6 to 1.0x10-1 M for CGE). The PME and CGE have limits of detection of 3.1x10-6 and 5.0x10-7 M, respectively, and response times of about 20 s. The potentiometric responses are independent of the pH of the test solution in the pH range 4.0-7.0. The proposed electrodes revealed good selectivities over a wide variety of other cations including alkali, alkaline earth, transition and heavy metal ions. The electrodes were successfully applied to the recovery of Sm3+ ion from tap water samples and also, as an indicator electrode, in potentiometric titration of samarium(III) ions
[en] The two-photon transition intensity of the (7F0)Γ1g→Γ1g(5D0) transition of the 4f6-ion Sm2+ in SrF2 has been investigated both in Judd-Pooler and direct formalisms. Although the agreement between the different calculations may be regarded as satisfactory, the direct calculation provides additional information concerning the transition intensity mechanism. The dominant pathway is found to involve the 4f55d1 intermediate core state 6H. The effects of changing the intermediate state baricenter have been investigated for both calculations, and the Judd-Pooler calculation becomes closer in agreement with the direct calculation as the energy baricenter increases. copyright 1997 The American Physical Society
[en] Highlights: ► SrMoO4:Sm3+ fluorescent nanofibers were fabricated by electrospinning. ► The properties of the SrMoO4:Sm3+ nanofibers were investigated. ► The obtained nanofibers exhibit a fine orange-red fluorescent property. ► The PL intensity of the nanofibers is superior to the nanoparticles counterpart. ► The optimum doping concentration of Sm3+ in the host lattice is 2 at.%. - Abstract: Samarium ions doped strontium molybdate (SrMoO4:Sm3+) nanofibers (NFs) were fabricated by a simple electrospinning process. The obtained SrMoO4:Sm3+ NFs are composed of scheelite-type tetragonal SrMoO4 phase, and the NFs have an average diameter of ca. 90 nm. Under 275 nm ultraviolet (UV) excitation, the NFs show an orange-red fluorescent property symbolized by a characteristic emission (606 nm) resulting from the 4G5/2 → 6H7/2 energy level transition of Sm3+. And the photoluminescence (PL) emissi on intensity of the SrMoO4:Sm3+ NFs is superior to that of the nanoparticles (NPs) counterpart under the same doping concentrations. The effect of Sm3+ concentrations on the 4G5/2 → 6H7/2 emission intensity was also investigated. The result reveals that the concentration quenching will occur when the Sm3+ content exceeds 2 at.%. In other words, the SrMoO4:Sm3+ NFs have an optimal luminescent performance under such a doping concentration.