Abstract: Gd_xBiY_2xFeO₁₂(x=0，0.1，0.2，0.4，0.6，0.8) nanocrystals were synthesized viathe solgel method. Samples were characterized by means of powder Xray diffraction (XRD), thermal gravity analysis (TGA) and differential thermal analysis 　(DTA), transmission electron microscopy　(TEM), vibrating sample magnetometer　(VSM). The average sizes of the particles were determined by virtue of Scherrer’s formula and were in a rang e of 43~50 nm. The effect of Gd³⁺ substitution for Y³⁺ on magnetic properties of BiY₂Fe₅O₁₂ was investigated. 

Key words: magnetic, bismuth--yttrium iron garnet, Bi-YIG, nanoparticles