A modified solution combustion method to superfine Gd2O3:Eu3+ phosphor: preparation, phase transformation and optical properties

Cubic and monoclinic Gd2O3:Eu3+ phosphors in the range of nano-scale and submicron-scale were prepared by a modified solution combustion method. Coexistence of cubic and monoclinic phases was found in the highest luminescent sample synthesized at 600 °C. In relation to commercial sample, the relative luminescence intensity was 49.8%. The shape of emission spectrum of the sample thus changed and the charge-transfer-state band of excitation spectrum slightly shift toward higher energies. With increasing the annealing temperature, phase transformation and correlative optical properties of Gd2O3:Eu3+ phosphors were studied. It was found that the samples were dominated by cubic structure and monoclinic structure at temperatures below and above 900 °C.