THE PREFERENTIAL SITE OCCUPATION AND MAGNETIC-PROPERTIES OF GDXY2-XO3

The gadolinium-yttrium mixed oxides GdxY2-xO3 were synthesized over a wide range of concentrations: x = 0.10, 0.18, 0.41, 0.74 and 1.26. The X-ray diffraction data from the polycrystalline samples were taken at room temperature and refined using the Rietveld method. Gadolinium-yt trium oxides crystallize in the space group Ia3. The cations occupy th e six coordinated positions 8b and 24d. The anion occupies a general t etrahedrally coordinated position. At concentrations x less-than-or-eq ual-to 0.41 gadolinium ion occupies exclusively 24d, but at higher con centrations the occupation of position 8b increases continuously. The magnetic susceptibility measurements showed the presence of the antife rromagnetic interaction in all samples. The magnetic moment in the sam ple x = 1.26 is significantly different from the magnetic moment of th e free ion Gd3+. The Curie-Weiss temperature shows a nonlinear depende nce on concentration.