Structural and Luminescence Behavior of Nanocrystalline Orthophosphate KMeY(PO4)2: Eu3+ (Me = Ca, Sr) Synthesized by Hydrothermal Method

Abstract

KMeY(PO4)2:5% Eu3+ phosphates have been synthesized by a novel hydrothermal method. Spectroscopic, structural, and morphological properties of the obtained samples were investigated by X-ray, TEM, Raman, infrared, absorption, and luminescence studies. The microscopic analysis of the obtained samples showed that the mean diameter of synthesized crystals was about 15 nm. The KCaY(PO4)2 and KSrY(PO4)2 compounds were isostructural and they crystallized in a rhabdophane-type hexagonal structure with the unit-cell parameters a = b ≈ 6.90 Å, c ≈ 6.34 Å, and a = b ≈ 7.00 Å, c ≈ 6.42 Å for the Ca and Sr compound, respectively. Spectroscopic investigations showed intense 5D0 → 7F4 transitions connected with D2 site symmetry of Eu3+ ions. Furthermore, for the sample annealed at 500 °C, europium ions were located in two optical sites, on the surface of grains and in the bulk. Thermal treatment of powders at high temperature provided better grain crystallinity and only one position of dopant in the crystalline structure. The most intense emission was possessed by the KSrY(PO4)2: 5%Eu3+ sample calcinated at 500 °C.

The Effects of Synthesis Techniques on the Photoluminescent Behaviours of the Nampo4:Ce3+ (M=Mg, Ca, Ba, Sr) Nanophosphors

“…Recently there has been rapid growth in research of phosphor materials for its wide range of luminescence applications in solid-state lighting devices [1,2]. Of particular interest, orthophosphates with formula of ABPO 4 (with A= alkaline metals and B = alkaline earth metals) has attracted much interest because of its intense luminescence emissions in the visible region and facile methods of preparation making them potential candidates for applications in colour display devices [3,4].…”