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-yttrium oxides crystallize in the space group Ia3. The cations occupy the six coordinated positions 8b and 24d. The anion occupies a general tetrahedrally coordinated position. At concentrations x less-than-or-equal-to 0.41 gadolinium ion occupies exclusively 24d, but at higher concentrations the occupation of position 8b increases continuously. The magnetic susceptibility measurements showed the presence of the antiferromagnetic interaction in all samples. The magnetic moment in the sample x = 1.26 is significantly different from the magnetic moment of the free ion Gd3+. The Curie-Weiss temperature shows a nonlinear dependence on concentration.