Concentration influence on temperature-dependent luminescence properties of samarium substituted strontium tetraborate

The series of divalent samarium substituted strontium tetraborate (Sr1-xSmxB4O7) polycrystalline samples were prepared by the conventional solid-state reaction. The phase formation of the samples was investigated by X-ray powder diffraction measurements. The luminescence spectra and decay curves of the Sm2+ ions were measured. Temperature dependent Sm2+ luminescence properties were investigated. The f-d and 5D1-7FJ transitions appeared at 350 K and increased with increase in the temperature while the intensity of 5D0-7FJ transitions decreased. The emission spectra pointed out that Sm2+ occupies of C2v or lower symmetry site. The photoluminescence decay times of strontium tetraborate doped with different concentrations of Sm2+ was investigated as a function of temperature in the range of 100-500 K. However, no obvious concentration quenching was observed. - Highlights: → Strontium tetraborate stabilizes divalent samarium. → Temperature dependent Sm2+ luminescence. → Sm2+ degeneracy is removed in low symmetry site. → Well resolved emission of Sm2+ under UV excitation.