The structure characteristics of the diluted magnetic semiconductor Y_2−xDy_xO₃

Abstract

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.

Structural and vibrational study of C-type doped rare earth sesquioxide Yb2−xCoxO3

“…If K is equal or close to 1, a random distribution is present. [20] and Gd 3+ in Er 2−x Gd x O 3 [21], which is attributed in the last case to the small difference in ionic radii of Er 3+ and Gd 3+ . Nevertheless, the cationic distribution, preferential or random, greatly depends on the preparation method [21].…”

X‐ray diffraction analysis of powder and thin film of (Gd1‐xYx)2O3 prepared by sol‐gel process

“…In a previous work [19,22], we found a similar random distribution of cations in (Er 1-q Gd q ) 2 O 3 and (Gd 1-q Ho q ) 2 O 3 which is attributed to the small difference in cationic radii. Depending on the difference in cationic radii, a random distribution is obtained whenever the difference between the cationic radii is small (e.g Y 2-q Re q O 3 , Re = Dy and Ho, [15,25], and preferential one is obtained for longer difference in radii (e.g Eu 2-q Yb q O 3 [20]; Y 2-q Gd q O 3 [26] and Y 2-q Eu q O 3 [17] ). Nevertheless, a random cationic distribution was found in Sm 2-q Y q O 3 [27] where partitioning was expected because of the relatively big difference in cationic radii.…”

Formation and characterization of nanocrystalline binary oxides of yttrium and rare earths metals

“…Binary oxides of yttrium and rare earths are used for their optical [1], dielectric [2,3] and other chemical and physical properties [4][5][6]. Whereas Y 2 O 3 has always the Mn 2 O 3 type cI80 cubic structure, the pure rare earths oxides have structures such as the La 2 O 3 type monoclinic, hP5 hexagonal, the Sm 3 O 4 type cI84 cubic, the Sm 2 O 3 type mC30 monoclinic, and the fluorite (CaF 2 ) type cF8 cubic [7].…”