Fe2O3 nanoparticles doped with La（Ⅲ） was prepared using iron citrate as starting material via sol-gel method.Iron oxide nanoparticles were characterized using X-ray diffration, transmission election mieroscope, FTIR and BET,respectively.There was no obvious phase transpfrmation for the sample doped with 4 wt% La2O3 after heating at 400℃ for 8h.This suggests that the transition of the γ-Fe2O3 to the α-Fe2O3,which is thermodynamically stable phase,be effectively suppressed by La（Ⅲ）doping.Meanwhile, the existence of La（Ⅲ）on the surfaces of the nanopar-ticles also takes the role of restraining the particles aggregation during heating process.
