Abstract:We present extensive first principles density functional theory (DFT) calculations dedicated to analyze the magnetic properties of Cr n (n = 2 and 3) impurities embedded in a Cu fcc matrix. We consider several dimers and trimers having different interatomic distances. In all cases the Cr atoms have been embedded as substitutional impurities in the metallic network. For the case of the dimers we have considered two magnetic configurations: Ferromagnetic (Antiferromagnetic) when the atomic magnetic moments are parallel (antiparallel) each other, for this case we have found that the lowest-energy state corresponds to the antiferromagnetic coupling between Cr atoms whose interatomic distance is a√2. In the case of the Cr trimers we have considered three or four magnetic configurations, depending on the Cr impurity geometry, for this case we have found that the lowest-energy state corresponds to the antiferromagnetic Cr trimer AF (↑,↓,↓) forming an isosceles right angle triangle whose hypotenuse and legs length are a√2 and a, respectively, with magnetic moments c (2) = 3.45/-3.32/3.45 μ B .