In this paper Mossbauer effect is used to investigate the variation of the properties of Y 2Fe 17 when some Ga atoms are in the place of Fe atoms.Results of experiment show that Y 2(Fe 1- x Ga x ) 17 turns from the Th 2Ni 17 composition to the Th 2Zn 17 composition according to the increase of x .Curie temperature and hyperfine field both have maximum when both compositions coexist.Furthermore,lattice parameters increase...