SYNTHESIS, CHARACTERIZATION AND EMISSION STUDIESOF Eu 3+ / Dy 3+ DOPED K2Mo4O13 PHOSPHORS
Alkali molybdates are of considerable interest due to their remarkable properties and possible applications. Potassium tetra molybdate (K2Mo4O13) was prepared by the standard solid-state method, while the rare earth (Eu3+ and Dy 3+ ) doped K2Mo4O13 compositions were obtained from a simple ion exchange method. The materials werecharacterised by powder X-ray diffraction (XRD), Scanning electron microscope-Energy dispersive spectroscopy(SEM-EDS), Fourier transform Infra-red spectroscopy (FT-IR) and Raman techniques. Parent K2Mo4O13, and Eu3+ / Dy 3+ doped K2Mo4O13 compositions formed a triclinic phase. The Infra-red and Raman spectra gave bands inthe400-1000 cm-1 , consistent with reported spectra. The SEM images consist of rod-like structures in both parent andLn-doped KMO. The EDS profiles of Ln (Ln = Eu and Dy) doped KMO consist of peaks corresponding to Ln, K, Mo and O. The photoluminescence (PL) excitation spectra are dominated by 4f-4f transitions. The PLexcitationspectra of Eu (Dy) consist of an intense peak at 395 nm (427 nm) and are related to the 7F0 →5L6 ( 6H15/2 →4G11/2) transition of the Ln ion and a few low-intense lines. The emission spectra of Eu (Dy) have a strong band at 615nm(638 nm) and are related to the transitions of 5D0 → 7F2 ( 4F9/2 → 6H11/2). The Eu (Dy) doped KMOphosphor materials emitted the red (deep red) colour light, which may be useful for the preparation of the W-LEDs.
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