Magnetism of small V clusters embedded in a Cu fcc matrix: an ab initio study

Abstract

We present extensive first principles density functional theory (DFT) calculations dedicated to analyze the magnetic and electronic properties of small Vn clusters (n=1,2,3,4,5,6) embedded in a Cu fcc matrix. We consider different cluster structures such as: i) a single V impurity, ii) several V2 dimers having different interatomic distance and varying local atomic environment, iii) V3 and iv) V4 clusters for which we assume compact as well as 2-and 1-dimensional atomic configurations and finally, in the case of the v) V5 and vi) V6 structures we consider a square pyramid and a square bipyramid together with linear arrays, respectively. In all cases, the V atoms are embedded as substitutional impurities in the Cu network. In general, and as in the free standing case, we have found that the V clusters tend to form compact atomic arrays within the cooper matrix. Our calculated non spin-polarized density of states at the V sites shows a complex peaked structure around the Fermi level that strongly changes as a function of both the interatomic distance and local atomic environment, a result that anticipates a non trivial magnetic behavior. In fact, our DFT calculations reveal, in each one of our clusters systems, the existence of different magnetic solutions (ferromagnetic, ferrimagnetic, and antiferromagnetic) with very small energy differences among them, a result that could lead to the existence of complex finite-temperature magnetic properties. Finally, we compare our results with recent experimental measurements.

Magnetism of Cr Impurities Embedded in Cu fcc Matrix: Density Functional Calculations

“…They studied V atoms embedded in a Cu matrix by means of XMCD. Félix-Medina et al [2] performed a theoretical study using DFT for small V clusters embedded in a Cu fcc matrix. Baker et al [3] studied Fe clusters embedded in an Ag matrix using Corresponding author: Juan Ulisses Gallardo Zazueta, research fields: magnetic nanostructures and ab initio calculations.…”