Y2o3:re nanoparticles

Abstract

The invention provides YO:RE nanoparticles having a cubic crystal structure, wherein RE is a trivalent rare earth metal ion. The invention further provides a method of preparing YO:RE nanoparticles, comprising: a) providing a mixture comprising (i) an yttrium salt and/or yttrium alkoxide, (ii) a rare earth metal salt and/or rare earth metal alkoxide, and (iii) an organic solvent; b) optionally, subjecting the mixture to a pre-treatment step which comprises heating the mixture at a temperature of at least 80° C. and/or at a temperature such that crystal water and/or organic impurities are removed, c) heating the mixture at a temperature between 220° C. and 320° C. and/or at a temperature such that a precursor complex forms; d) subjecting the mixture to a precipitation stage, wherein a precipitate forms, said precipitation stage preferably comprising allowing the mixture to cool and/or adding an antisolvent to the mixture; and e) heating the precipitate at a temperature between 600° C. and 900° C. and/or at a temperature such that a cubic YOcrystal structure forms, preferably for at least 10 minutes.