The structure of Si-doped γ-Fe2O3 small particles prepard by doping with different silicon content has ben investigated by X-ray diffraction based on Furuhashi method. The results show that the lattice parameters decrease continuously with increasing silicon content, which suggests an evidence of a solid solution for Si-doped γ-Fe2O3. The Si^4^+ cation in the like-spinels appears a strong tendency to distribution in the tetrahedral site. The oxygen parameter as well as the mean size of interstices of tetrahedral and octahedral also appears a certain influence of silicon doping. Additionally, grain sizes and lattice distortions of the samples which were calculated following the Stokes and Wilson formula indicate a significant decrease for the grain size with increasing silicon content and a little change for the lattice distortion. Finally, the coercivity and saturation magnetization of the Si-doped γ-Fe2O3 particles are discussed.

Key words: SILICON, X-RAY DIFFRACTION ANALYSIS, IRON OXIDE, DOPE, MAGNETISM