Synthesis and luminescent properties of sub-5-nm lanthanide oxides nanoparticles

We introduce a new method for the synthesis of luminescent nano-sized particles. Ultrafine, equiaxed and monodisperse rare-earth oxide particles with an average grain diameter in the range 2-5 nm have been prepared by applying direct precipitation from high-boiling polyalcohol solutions. Colloidally stable suspension of luminescent nanoparticles is formed. The lanthanide doped nanoparticles are easily, quantitatively and reproducibly prepared. The materials have been characterized by using high-resolution TEM, absorption spectroscopy and luminescence spectroscopy. A very significant modification of the luminescent properties is observed. Lanthanide sesquioxides Ln(2)O(3) and doped Ln(3+) yttrium or gadolinium oxides are presented (Ln = Eu, Tb, Nd). (C) 2002 Elsevier Science B.V. All rights reserved.