Magnetism in small bimetallic Mn-Co clusters

Abstract

Effects of alloying on the electronic and magnetic properties of MnxCoy (x + y=n=2-5; x=0-n) and Mn2Co11 nanoalloy clusters are investigated using the density functional theory (DFT). Unlike the bulk alloy, the Co-rich clusters are found to be ferromagnetic and the magnetic moment increases with Mn-concentration, and is larger than the moment of pure Con clusters of same size. For a particular sized cluster the magnetic moment increases by 2 µB/Mn-substitution, which is found to be independent of the size and composition. All these results are in good agreement with recent Stern-Gerlach (SG) experiments [Phys. Rev. B 75, 014401 (2007) and Phys. Rev. Lett. 98, 113401 (2007)]. Likewise in bulk MnxCo1−x alloy, the local Co-moment decreases with increasing Mn-concentration.

Electronic and magnetic properties ofConMomnanoclusters from density functional calculations (n+m=xand 2Liebing1, Martín2, Trepte3 et al. 2015Phys. Rev. B

“…This includes four short bonds and two longer bonds forming again a flattened tetrahedron, which is in line with previous studies [11][12][13]15,19,[70][71][72][73] . Other studies 14,20,59 predict a slightly out-of plane rhombus to be the ground state.…”

“…[14,16,20,59]) and S = 5 2 (see Ref. [11,13,15,19] In the present study we also observe a structure with S = 7 2 which is only 4.5 meV higher in energy than the actual ground state of S = 5 2 . The magnetic ground state depends therefore crucially on the actual geometry.…”

“…There is an ongoing discussion in literature regarding the energetically favored alignment of three Co atoms. Sebetci 20 and Ma et al 59 predict a linear structure to be the most stable one, whereas several other authors 11,[13][14][15][16]19 find a triangular structure to be the ground state. According to our calculations the triangular structure is more stable than the linear one and vibrational stable.…”

“…These properties govern the possible applicability of the clusters. There are also a few studies on mixed cobalt clusters, for example in combination with manganese 11 and copper 12 . Here we present a density functional theory (DFT) study of the Co n Mo m nanoclusters with n+m = x and 2≤x≤6 atoms on the all-electron level using the generalized gradient approximation (GGA).…”

Structure, reactivity, and electronic properties of V-doped Co clusters

“…This HCP to icosahedron structural transition has also been reported previously for Mn doping in Co 13 cluster. 34 Finally, the single V atom likes to fit at the center of the icosahedron and it is ferrimagnetically coupled with the surface Co atoms. The first isomer is also a central V-atom-doped icosahedral Co 12 V cluster, with total magnetic moment 23 B and it is about 0.46 eV above the MES.…”