Combustion synthesis and photoluminescence of Eu3+ doped LaAlO3 nanophosphors

Eu3+ doped LaAlO3 nanophosphors were successfully synthesized by a combustion process using concentrated solution of lanthanum nitrates and aluminate as oxidiser, and glycine acid as fuel. The powders were characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fluorescence spectroscopy. Pure LaAlO3 phase was obtained at 800 C heated for 4 h, without formation of any intermediate phase, with an average crystal size, as determined by TEM, of 60 nm. Intense photoluminescence emission is reported at 616 nm, allowing the use of this material as red phosphor

Hydrothermal synthesis and luminescence properties of nanospherical SiO 2 @LaPO 4 :Eu 3+ (5%) composite

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Spectroscopic investigations of Sm3+doped phosphate glasses: Judd-Ofelt analysis

Highlights- Sm3+-doped Phosphate glasses were prepared by the conventional melt quenching method.- Judd-Ofelt intensity parameters, Ω2, Ω4, and Ω6 were determined and discussed.- Some radiatives parameters of Sm3+ were estimated.- Obtained results make our glasses suitable for laser emission.International audiencePhosphate glasses with chemical compositions of (42– x/2) P2O5-(42– x/2)Na2O-15ZnO–xSm2O3 were synthetized by melt quenching method. We investigated the influence of Sm3+ doping on the optical properties of phosphate glasses. X-Ray Diffraction indicates that the samples have an amorphous structure. DSC measurements show a good thermal stability of phosphate glasses. Using the absorption spectra, Judd-Ofelt analysis was applied to absorption bands of Sm3+ (4f5) to carry out the three phenomenological parameters of Judd-Ofelt (JO). According to the obtained values of Ω2, Ω4 and Ω6, some radiative properties were theoretically determined. Photoluminescence (PL) spectra show three transitions of Sm3+: 4G5/2 → 6H5/2 (600 nm), 4G5/2 → 6H7/2 (564 nm) and 4G5/2 → 6H9/2 (645 nm). The concentration dependency of PL intensity was investigated. The quenching of the PL intensity occurs at the Sm3+ concentration above 1%. The predicted lifetime (τr) calculated by using JO method and the measured lifetime (τmea) determined experimentally for 4G5/2 level, were discussed and compared with those of other works. With the weak spectroscopic quality factors Ω4/Ω6 (0.76), we expect a relatively prominent infrared laser emission