Luminescence and cathodoluminescence properties of M^IPr(PO_3)_4(M^I=Na, Li,K) and PrP_5O_14

Poly-crystals of praseodymium phosphate M^IPr(PO_3)_4 (M^I=Na, Li, K) and PrP_5O_14 have been synthesized by the flux method. All of these hosts crystallized in the monoclinic structures with different space groups. The spectroscopic properties of trivalent praseodymium ions in these compounds have been characterized. The emission spectra under laser excitation at 488 nm show several characteristic emission bands of Pr^3+ resulting from intra-configurational transitions between ^3^P_0 and 4f^2 lower lying levels. All the studied compounds exhibit two strong parity-allowed 4f^15d^1 -> 4f^2 emission bands located in the near ultraviolet domain using electrons as source for optical excitation. Therefore, these materials are of interest for applications in lighting and scintillating applications

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

Combustion synthesis and photoluminescence of Tb3+ doped LaAlO3 nanophosphors

Terbium doped lanthanum aluminate (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), Rietveld refinement, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fluorescence spectroscopy. Pure LaAlO3 phase was obtained at 800 degrees C heated for 4 h, without formation of any intermediate phase, with an average crystal size, as determined by TEM, of 60 nm. Intense green emission is reported at 542 nm, from the D-5(4) level, which intensity depends on Tb concentration. (C) 2013 Elsevier B.V. All rights reserved

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