The solid solutions Y2−xDyxO3 (x=0.20,0.50,0.74,1.40,1.80) were obtained by ceramic technology. The crystal structures were refined from X-ray and neutron diffraction data measurements in the cubic space group Ia3 by the Rietveld method. The unit cell dimensions varied from 10.6056(4) Å to 10.6624(1) Å. The structure characteristics were analyzed in relation to the concentration of the magnetic ion. The selected cation–anion–cation bonds, important for the understanding of the superexchange interaction and the magnetic properties, are given. In all samples the Dy3+ ions are randomly distributed in the cation sites 8(b) and 24(d). Comparing the random cation distribution in Y2−xDyxO3 and the preferential distribution in Y2−xGdxO3, it has been concluded that the type of distribution depends on the difference of the lattice constants between RE2O3 and Y2O3. Hence, in this cubic Mn2O3-type of structure, a preferential distribution can be expected in Y2−xNdxO3, Y2−xSmxO3, Y2−xEuxO3, Y2−xLuxO3, and a random distribution in Y2−xHoxO3.

X-ray powder diffraction data for three new bismuth yttrium ytterbium oxide compounds synthesized by solid-state reaction method are reported. The unit-cell dimensions were determined from X-ray diffraction method using Cu Kα radiation and evaluated by indexing programs. The cubic δ-Bi2O3 phase was identified to be the sole crystalline phase in Bi0.82Y0.09Yb0.09O1.5, Bi0.82Y0.12Yb0.06O1.5, and Bi0.82Y0.06Yb0.12O1.5 with lattice constants of a=5.5110(3), 5.5154(2), and 5.5113(2) Å, respectively.

New bismuth yttrium gadolinium oxide, Bi1.8Y0.1Gd0.1O3, synthesized from a stoichiometric mixture of Bi2O3, Y2O3, and Gd2O3, was characterized by X-ray powder diffraction. The compound was determined to be tetragonal, with space group P421c (114), unit-cell parameters of a=7.793 08(29) and c=5.665 71(40) Å, and the number of formulas per unit cell Z=4. Bi1.8Y0.1Gd0.1O3 is isostructural with β-Bi2O3.