Europium-doped Lu2O3 phosphors prepared by a sol-gel method

Abstract

Cubic lutetium sesquioxide (Lu2O3) presents a suitable host material because of its favourable properties including chemical and phase stability. Lu2O3 has a wide band gap (> 5.5 eV) and its doping with lanthanide ions, which behave as activators, gives rise to some unique optical properties. Also, due to a high effective atomic number (Zeff = 68.8) and high density (9.42 g/cm3) of the Lu2O3 host, providing high stopping power for ionizing radiation, it has also attracted attention as a scintillator material. Since optical properties are affected by both crystal structure and morphology, which depend strongly on the synthesis method and conditions employed, many different methods have been studied for its synthesis. However, due to high melting temperature of Lu2O3 (2490 °C), the preparation of single crystals is difficult. In our work, we prepared polycrystalline samples of Eu:Lu2O3 using a sol-gel route based on the Pechini polycondensation. We tested three europium doping concentrations, two different annealing regimes were examined as well. The influence of mentioned parameters on photoluminescent and radioluminescent properties was established. Our samples proved that the used synthesis method can be used for further research of Lu2O3 doped with other rare-earth metals.