Synthesis of non-toxic phosphor material based on pyrochlore-type dititanate (Eu3+/Y2Ti2O7)

Abstract New photoluminescent, non-toxic europium doped yttrium titanate phosphors ( x  mol% Eu 3+ /Y 2 Ti 2 O 7 where x  = 1.0, 2.0, 4.0 6.0, 10, 15 and 30 mol%) with high crystalline structure were synthesized by sol–gel followed by heat treatment at 1000 °C for 5 h. Eu 3+ /Y 2 Ti 2 O 7 phosphors were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), FT-IR and photoluminescence (PL) spectroscopy. The effects of heat treatment and europium metal ion concentration on the structure and PL properties were investigated. Eu 3+ /Y 2 Ti 2 O 7 phosphors exhibited micro spherical shape with average crystal size from 90 to 144 nm. The PL spectra showed the orange red emission bands of Eu 3+ in highly symmetrical host. The longest PL lifetime was detected at 4 mol% Eu 3+ /Y 2 Ti 2 O 7 phosphor. The toxicity of 15 mol% Eu 3+ :Y 2 Ti 2 O 7 was tested. The obtained result showed LD 50 is 3.2 g/kg. The PL and toxicity properties of the prepared phosphors make them promising materials for the future optical and biological applications.