MAGNETIC-ORDERING IN FE-DOPED GD2BACUO5

The structural and magnetic properties of iron-doped Gd2BaCuO5 have be en studied by X-ray diffractometry, Mossbauer spectroscopy and suscept ibility measurements. Mossbauer data on Gd2BaCu0.8Fe0.2O5 show that at room temperature Fe is not magnetically ordered, displaying hyperfine parameters similar to those generally assigned to Fe at Cu(2) sites i n the GdBa2(Cu1-xFex)3O7 superconductor. Susceptibility measurements d emonstrate that Gd2BaCu1-xFexO5 behaves like a three-dimensional antif erromagnet with T(N) = 11.9 +/- 0.1 K, independent of x. The effective magnetic moment calculated within a mean field approximation is consi stent with an ordering of the Gd sublattice.