LAUSR

Abstract Sodium praseodymium orthophosphate Na 3 Pr(PO 4 ) 2 was prepared using high temperature molten salt method and structurally characterized by single-crystal X-ray diffraction (SC-XRD) analysis. Its structure can be modeled as a four-dimensional (4D) commensurately modulated structure with orthorhombic superspace group Pca 2 1 (0 1/3 0)000 or as a conventional 3D superstructure description. The structure contains PrO 8 , NaO 6 , NaO 7 and PO 4 polyhedra, which are in six types of linear array along the a -axis. Furthermore, the excitation and emission spectra, decay time and Commission International de l’Eclairage (CIE) chromaticity index of Na 3 Pr(PO 4 ) 2 were studied. Under blue light excitation (468 nm), the powdered Na 3 Pr(PO 4 ) 2 calcined at 1200 °C shows the strongest red emission at around 610 nm, which originates from the 3 P 0 → 3 H 6 and 1 D 2 → 3 H 4 transformations of Pr 3+ ion.