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This article reports on the optical properties of cadmium bismuth borate (CdBiB) glasses doped with various concentrations of Sm 3+ ions. FT-IR spectra of Sm 3+ :CdBiB glasses have been used to identify the functional groups present in the composition of the glasses. The emission spectra of Sm 3+ :CdBiB glasses have shown an intense reddish-orange emission at 600 nm ( 4 G 5/2 → 6 H 7/2 ). From the absorption spectrum, the experimental oscillator strengths were determined and have been used to calculate the Judd–Ofelt (J–O) intensity parameters. By using the J–O intensity parameters, various radiative properties have been studied and computed for the various transitions of Sm 3+ :CdBiB glasses. Based on the values of stimulated emission cross section, radiative transition rate and the branching ratio of the emission transition 4 G 5/2 → 6 H 7/2 , it is suggested that 1.0 mol% of Sm 3+ :CdBiB glass is the promising luminescent material towards lasing applications. The nature of luminescence decay curves of 4 G 5/2 level with different concentrations of Sm 3+ :CdBiB glasses are also reported.

This study reports on the concentration dependent fluorescence properties of Tb3+-doped lead containing calcium zinc sodium fluoroborate (LCZSFB) glasses and are analyzed by DSC, FT-IR, FT-Raman, optical absorption, emission and decay curve spectra. Co-existence of trigonal BO3 and tetrahedral BO4 units was evidenced by FT-IR and Raman spectroscopy. Judd–Ofelt theory was applied to the experimental oscillator strengths to evaluate the J–O intensity parameters. The fluorescence spectra of Tb3+-doped glasses have revealed prominent blue and green emissions originating from 5D3 and 5D4 excited levels to 7FJ ground state multiplet, respectively. The luminescent intensity of the transitions originating from 5D4 state increases with increase of Tb3+ concentration and no quenching effect is noticed up to 2 mol% of Tb3+ ions. Chromaticity color coordinates have been calculated and the dominant emission in the green region is discussed. The nature of decay curves of 5D4 level for different Tb3+ ion concentration in all LCZSFB glasses has been analyzed. Using the J–O intensity parameters as well as from the emission and decay curve measurements, various radiative and fluorescence properties have been calculated for the 5D4 fluorescent level. Based on these results, the utility of Tb3+ ions doped LCZSFB glasses as laser active materials for high intensity emissions in the green region is discussed.

Rare earth ions (Sm 3+ and Dy 3+ ) activated calcium gadolinium tungstate [Ca 2 Gd 2 W 3 O 14 ] powder phosphors were synthesized by solid state reaction method at 1000 °C. The obtained phosphors were characterized by XRD, SEM, EDAX, FTIR and PL spectroscopy. The results of XRD patterns indicate the tetragonal phase structure of Sm 3+ and Dy 3+ : Ca 2 Gd 2 W 3 O 14 phosphors. From the SEM images of Sm 3+ and Dy 3+ : Ca 2 Gd 2 W 3 O 14 phosphors, it is observed that the average grain size is in the range 100–250 nm. The functional groups are identified by using the FTIR spectra and the elements present in the composition are confirmed by the EDAX profiles. Emission spectra of Sm 3+ : Ca 2 Gd 2 W 3 O 14 powder phosphors have shown strong red emission at 646 nm ( 4 G 5/2 → 6 H 9/2 ) with an excitation wavelength λ exci = 402 nm ( 6 H 5/2 → 4 F 7/2 ) and Dy 3+ : Ca 2 Gd 2 W 3 O 14 phosphors have shown yellow emission at 574 nm ( 4 F 9/2 → 6 H 13/2 ) with an excitation wavelength λ exci = 385 nm ( 6 H 15/2 → 4 I 13/2 ).

EPR and optical absorption spectra of Mn2+ ions doped in potassium thiourea bromide (KTB) single crystals have been studied. The EPR spectrum at room temperature exhibits an isotropic sextet hyperfine pattern which is characteristic of Mn2+ ions. EPR spectra have been studied at different temperatures from 123 to 295 K. The EPR spectra clearly demonstrate that, thiourea plays an important role in modifying the properties of crystal lattices which is expected due to the ferroelectric behavior of thiourea molecule in the complexes. In the temperature range studied, at ∼243 K, a sudden change in the EPR spectrum is observed and the temperature dependant EPR spectra are discussed in this model compound K[CS(NH2)2]4Br. The optical absorption spectrum at room temperature exhibits bands characteristic of Mn2+ ions in an octahedral symmetry. From the observed UV–VIS absorption spectrum, the crystal field splitting parameter Dq and the Racah inter-electronic repulsion parameters B and C have been evaluated and discussed accordingly. The infrared spectrum confirms the composition of several functional group vibrations of O–H, C–S and C–N of PTB crystal lattice.