Synthesis of Gd₂O₃ nanoparticles for MRI contrast agents

Gd₂O₃ nanoparticles were synthesized by using our original method for application as MRI contrast agents. The sample diameters were controlled in the range 18–66 nm by adjusting the annealing temperature between 773 and 1273 K in air or in an Ar atmosphere. Magnetization measurements were performed at 300 K, and the effective magnetic moment of each sample was calculated. They showed paramagnetism at 300 K and they had large effective magnetic moment μ_eff of 7.15–8.05 μ_B. MRI measurements were performed in 0.8 wt% agarose solution, and the Gd₂O₃ nanoparticles were found to work as effective T₁-shortening MRI contrast agents.