Spectroscopic properties of Eu3+-doped KLa(PO3)4 and LiLa(PO3)4 powders

Abstract KLa(PO3)4 (KLP) and LiLa(PO3)4 (LLP) doped with different concentrations of Eu3+ are grown by solid state reaction. The obtained powders are identified by X-ray diffraction, Raman and FT-IR spectroscopies. These polyphosphates KLa(PO3)4 and LiLa(PO3)4 crystallize in the monoclinic system but with different space groups respectively P21 and C2/c. The evolution of crystal lattice parameters as function of Eu3+ concentration in these host lattices was studied. Spectroscopic properties of the Eu3+-doped KLa(PO3)4 and LiLa(PO3)4 at room temperature (RT) are presented. The excitation spectra of the Eu3+ ion in condensed polyphosphates along the UV–Visible domain are registered. They show that the position of the charge transfer band (CTB) depends on the host lattices. The effect of structural characteristics of condensed polyphosphates on their optical and colorimetric properties was investigated for the first time. Colorimetric parameters of the Eu3+ ions red emission in KLP and LLP are determined and compared with other host matrices. Evolution of colorimetric properties as function of Eu3+concentration was discussed.