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 °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 (5D0 → 7F1) at 590 nm dominates over that of electric dipole transition (5D0 → 7F2) at 617 nm. The optimum concentration of Eu3+ for the highest luminescence is found to be 7 at.%. Emission from the 5D0 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.