Preparation, structural analysis and luminescence properties of nanocrystalline phosphor Gd₂O₃:Eu

Nanocrystalline monoclinic and cubic Gd₂O₃:Eu with different Eu³⁺ concentration were prepared using glycine-nitrate combustion synthesis. By changing the ratio of glycine to nitrate and proper heat treatment, pure monoclinic and cubic Gd₂O₃:Eu with particle size less than 40 nm can be easily formed. Under ultraviolet excitation, main emission of Eu³⁺(⁵D₀ → ⁷F₂) locates at 624 nm in monoclinic Gd₂O₃:Eu and 611 nm in cubic sample, In excitation spectrum, two broad bands corresponding to the host absorption and charge transfer state (CTS) and f-f transitions of Gd³⁺ and Eu³⁺ were observed and discussed. The quenching concentration of monoclinic and cubic Gd₂O₃:Eu is 10% and 15%, respectively, both of which are much higher than that of bulk Gd₂O₃:Eu.