Synthesis and characterization of undoped and Mn(II)ions doped Li2CaAl4(PO4)4F4 nanophosphors

• The prepared undoped and Mn(II) ions doped Li2CaAl4(PO4)4F4 phosphors are in nano size.
• The site symmetry of Mn(II) ions doped Li2CaAl4(PO4)4F4 phosphor is attributed to distorted octahedral symmetry.
• FT-IR spectra exhibit the various vibrational modes of phosphate ions and water molecules.

Undoped and Mn(II) ions doped Li2CaAl4(PO4)4F4 have been synthesized by conventional solid state reaction method and characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrum (EDS), transmission electron microscopy (TEM), optical absorption, Electron Paramagnetic Resonance (EPR), Photoluminescence (PL) and FT-IR techniques. The average crystallite sizes of prepared samples were calculated from the XRD data around 31 and 48 nm. SEM and TEM images show rods and irregular shaped particles respectively. Optical absorption spectra exhibit the characteristic absorption bands of Mn(II) ions in distorted octahedral site symmetry. EPR spectrum exhibit resonance signal at g = 2.01. PL spectrum of undoped and Mn(II) ions doped phosphor exhibited emission peaks from blue to red region and corresponding CIE coordinates are also calculated. FT-IR spectrum of prepared samples clearly exhibited the different vibrational bands and assigned to the phosphate ions and water molecules.

To confirm the morphology of Mn(II) ions doped Li2CaAl4(PO4)4F4 phosphor, TEM images were recorded. Obviously, well separated individual non-uniform rods and aggregates of various sized particle like structures are noted in the TEM images in the range of 0.2–0.5 μm. It is observed that the morphology of the prepared Mn(II) ions doped phosphor powders is polycrystalline constituted by microcrystalline structures.Figure optionsDownload as PowerPoint slide