Low temperature synthesis and luminescence properties of re-dispersible Eu3+ doped LaPO4 nanorods by ethylene glycol route

Eu3+ doped LaPO4 nanorods with monoclinic system have been prepared at relatively low temperature (150 degrees C) in ethylene glycol medium. Unit cell volume of LaPO4 is found to decrease linearly with increasing Eu3+ concentration indicating the homogeneous substitution of La3+ ions in LaPO4 by Eu3+ ions. Transmission electron microscopic images show that the particles are present in the form of nanorods having a length of 100 nm and diameter of about 20 nm. The photoluminescence study shows that the intensity of magnetic dipole transition (D-5(0) -> F-7(1)) at 590 nm dominates over that of electric dipole transition (D-5(0) -> F-7(2)) at 617 nm. The optimum concentration of Eu3+ for the highest luminescence is found to be 7 at.%. Emission from the D-5(0) level of Eu3+ follows monoexponential decay which can be attributed to homogeneous substitution of La3+ sites in LaPO4 by Eu3+ ions. As-prepared samples are found to be dispersible in methanol and water. This could be a potential candidate for various applications, i.e. incorporation of luminescent materials in polymer such as polyvinyl alcohol and in biological activity such as tracer. (c) 2010 Elsevier B.V. All rights reserved.