Comparative DFT study of structure and magnetism of TMnOm (TM = Sc–Mn, n = 1–2, m = 1–6) Clusters

Abstract

A systematic theoretical study of the structural and magnetic properties of small transition metal oxide clusters TM(n)O(m) (TM = Sc, Ti, V, Cr and Mn; n = 1, 2; m = 1-6) has been carried out by using an ab initio density functional theory approach. The O atoms are partly molecularly adsorbed in O-rich and few-valence electron TM oxide clusters like ScO(3), TiO(3), Sc(2)O(4-6), Ti(2)O(5-6), and V(2)O(6). The binding energy increases monotonously with increasing O atoms and decreases with the appearance of the peroxide unit, with the exception of ScO(3). The Sc-, Ti- and V- oxide clusters have a stronger binding than the Cr- and Mn-oxide ones. The magnetic properties are dependent on the TM element and on the density of O. The successive addition of an O atom to Mn(2) induces an odd-even magnetic oscillation from antiferromagnetic to ferrimagnetic and to nonmagnetic state. In the V-, Cr- and Mn-oxide clusters, the O atoms play a negligible role in the magnetism and they are generally antiferromagnetic when coupled with TM atoms, while the O atoms possess large magnetic moments in some Sc- and Ti- oxide clusters.

Ab Initio Study of Structure and Magnetism of Late Transition Metal Oxide TMnOm Clusters (TM = Fe, Co, Ni, n = 1, 2, m = 1–6)

“…The most stable structure of Ni 2 O 4 is a planar configuration in an antiferromagnetic state and two terminal O atoms forming a peroxide unit, different from the cases of Fe 2 O 4 and Co 2 O 4 . The energetically preferred magnetic states are triplet and singlet, respectively, for Ni 2 O 5 and Ni 2 O 6 , and the terminal O atoms also prefer to form peroxide units.From above discussions, together with our earlier results of TM n O m (TM = Sc, Ti, V, Cr and Mn, n = 1 and 2, m = 1-6),8 we found that transition metal oxide clusters prefer tridimensional architectures from Sc to Fe, while Co Delivered by Ingenta to: McMaster University IP: 91.200.81.113 On: Fri, 10 Jun 2016 12:37:48 Copyright: American Scientific Publishers Wang et al Ab Initio Study of Structure and Magnetism of Late Transition Metal Oxide TM n O m Clusters and Ni oxide clusters tend to adopt planar conformations and the terminal O atoms are inclined to form peroxide unit with increasing concentration of O atom. The specific physical reason is still unclear to us.…”

“…31 This method has been verified well to describe the interaction between TM and O in our previous work. 8 [32][33][34][35] Therefore, we believe this method can give a good description of the interaction between TM and O atoms. We considered many possible initial configurations to identify the low-lying and the ground state structure of these TM n O m clusters.…”

Metall‐Metall‐Mehrfachbindung oder keine Bindung? Die elektronische Struktur von V2O2

“…[28] Daneben gibt es mehrere rechnerische Studien zu V 2 O 2 ,d ie alle eine rhombische Struktur aber verschiedene elektronische Zustände vorhersagen. Wang,Gong und Wang [34] bestimmten mit dem PBE-Funktional einen Grundzustand mit Symmetriebruch (DND-Basissatz), lieferten aber keine weiteren Informationen, nicht einmal den V-O-Abstand. Jakubikova, RappØ und Bernstein [33] fanden mit dem BPW91-Funktional und dem LANL2DZ-Basissatz einen 7 A''-Zustand.…”

Structural and electronic properties of ScnOm(n=1−3Yang1, Liu2, Zhang3 2011Phys. Rev. B8020View full textAdd to dashboardCite

“…For example, small clusters like (ZnO) n , (V 2 O 5 ) n , (CrO 3 ) n form planar structures with very small sizes, and some small clusters present novel magnetic properties 8, [10][11][12] . For scandium (Sc), continuous interests are shown for several reasons.…”

“…Transition metal oxide clusters have attracted enormous attention because their structural, electronic, and magnetic properties are often quite different from those in their bulk phase [1][2][3][4][5][6][7][8][9][10] . For example, small clusters like (ZnO) n , (V 2 O 5 ) n , (CrO 3 ) n form planar structures with very small sizes, and some small clusters present novel magnetic properties 8, [10][11][12] .…”