Homogeneously precipitated Lu2O3:Eu nanocrystalline phosphor for X-ray detection

Nanocrystalline Lu2O3 doped with 1 at.% of Eu was obtained precipitating hydroxide of lutetium with urea at 80 °C from water solution and decomposing the hydroxide to oxide at 500 °C. Polyvinyl alcohol was used to hinder the particles growth during precipitation. The average size of the fabricated particles was 2-5 nm. Although at 500 °C the hydroxide decomposed to Eu-doped Lu2O3 traces of OH impurities were present in the material unless heated at 1200 °C. Radioluminescence was very poor for samples heated at 800 °C or lower temperature. After heating the precipitated powder at or above 1200 °C the efficiency jumped 45 times reaching 75% of the output from commercial microcrystalline Gd2O2S:Eu. The properties make nanocrystalline Lu2O3:Eu prepared in the described way a promising X-ray phosphor for planar digital medical imaging.