Orientation effects on the magnetic properties of a pair Cr₆ and V₆ atomic clusters embedded in bulk Fe

Abstract

The magnetic and electronic properties of a pair Cr 6 and V 6 atomic clusters embedded in bulk Fe are determined by using a realistic spd-band Hubbard-like model. The spin density distribution is calculated self-consistently in the unrestricted Hartree-Fock approximation. The local magnetic moments mðiÞ and the density of electronic states q i ðeÞ are obtained at various atoms i of the cluster and of the surrounding Fe matrix. We consider two different orientations between the clusters, or better still the axis of symmetry of the clusters: collinear (C) and non-collinear (NC). For all the cases studied the interface magnetic coupling between cluster and matrix moments is antiparallel. The Fe moments close to the cluster are slighty reduced, and the mðiÞ of Cr and V atoms at the interface are often much larger than the Cr bulk moments (e.g. mðiÞ ¼ À1:39m B for Cr 6 in Fe in both orientations). We compare the results with the corresponding results for just one Cr 6 and V 6 atomic cluster embedded in bulk Fe.

Proximity effects on the local magnetic moments of clusters V6–V9 embedded in a Fe matrix

“…When 3d transition metals are combined, the magnetic properties of the interface are influenced by the hybridization of the 3d orbitals. A ferromagnetic material can induce, via these d-d hybridizations, a magnetic order in the former paramagnetic material, like V at the interface with Fe; theoretical [3][4][5][6] and experimental [7,8] results confirm this fact. This behavior has motivated the production and experimental study of a large variety of complex magnetic materials involving transition metals in different geometrical arrangements: trilayers [9], superlattices [10], multilayers [11].…”

“…For simplicity, we ignore the differences between s and p integrals (i.e., U ss = U sp = U pp and U sd = U dd ) and we take the ratios between the direct Coulomb integrals U ss :U sd :U dd from atomic Hartree-Fock calculations [29]. With these approximations, the magnetic properties of TM nanostructured systems [6,3,4,22], have been studied and their results are in good agreement with experimental and another theoretical results.…”

“…Therefore a large number of atoms (about 25,000-40,000) is involved in the real-space expansion. This model has been used in several calculations of this type, for example, in the study of the magnetism of Fe 1 /V N nanoinclusions embedded in a Fe matrix [3], interacting Cr clusters in a Fe matrix [4], V N free atomic clusters [22], free Co N atomic clusters with mixed structures [23], and Co clusters on Pd surface [24]. The parameters used in the calculations are determined as follows.…”

Evidence of Clustering in Heusler like Ferromagnetic Alloys

“…The study of clustering effects is important in both nano as well as bulk materials. It is possible to modify the magnetic properties of such materials by the introduction of proper element to prepare the alloys [3,4]. In this paper we report the results of Mössbauer studies using Fe-57 and Sn-119 on the Heusler like alloys Fe 2 CrAl and Mn 2 CoSn.…”