The structure characteristics of the diluted magnetic semiconductor Y _2−x Dy _x O ₃

Abstract

The solid solutions Y 2−x Dy x O 3 (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 Dy 3+ ions are randomly distributed in the cation sites 8(b) and 24(d). Comparing the random cation distribution in Y 2−x Dy x O 3 and the preferential distribution in Y 2−x Gd x O 3 , it has been concluded that the type of distribution depends on the difference of the lattice constants between RE 2 O 3 and Y 2 O 3 . Hence, in this cubic Mn 2 O 3 -type of structure, a preferential distribution can be expected in Y 2−x Nd x O 3 , Y 2−x Sm x O 3 , Y 2−x Eu x O 3 , Y 2−x Lu x O 3 , and a random distribution in Y 2−x Ho x O 3 .