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Phys. Rev. B 50, 3899–3906 (1994)

[Issue 6 – 1 August 1994 ]

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Magnetic and electronic properties of substitutional Fe_N cluster impurities in Cr: Transition from antiferromagnetic to ferromagnetic Fe_N

A. Vega and L. C. Balbás

Departamento de Física Teórica, Universidad de Valladolid, E-47011 Valladolid, Spain

J. Dorantes–Dávila

Instituto de Física ``Manuel Sandoval Vallarta,'' Universidad Autónoma de San Luis Potosí, 78000 San Luis Potosí, Mexico

G. M. Pastor

Institut für Theoretische Physik der Universität zu Köln, Zülpicher Strasse 77, W-50937 Köln, Germany

We present a study of the magnetic and electronic properties of Fe_N clusters embedded in antiferromagnetic bcc Cr. The spin-polarized charge distribution is determined self-consistently by solving a realistic spd-band model Hamiltonian including intra-atomic Coulomb interactions in the unrestricted Hartree-Fock approximation. For all the studied clusters (N <= 51), the local magnetc moments at Fe atoms close to the Fe-Cr interface, as well as the average magnetic moment of the Fe_N impurity, are reduced with respect to the Fe bulk magnetization. The magnetic order within Fe_N changes from antiferromagneticlike to ferromagneticlike with increasing cluster size. The calculated critical size for this transition is N_c~=6. Results for the spatial distribution of the magnetic moments and for the local electronic densities of states are given for different N. The role of the structural and chemical local environment of the atoms on the electronic and magnetic properties is discussed, and our results are compared with those found for Fe/Cr multilayers. Some of the implications of the present study for magnetic alloys and ferromagnetic clusters on surfaces are pointed out.

©1994 The American Physical Society

URL: http://link.aps.org/abstract/PRB/v50/p3899
DOI: 10.1103/PhysRevB.50.3899
PACS: 75.60.Jp, 75.50.Rr, 75.50.Bb

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22. For other matrices (e.g., V) the charge transfer may be somewhat larger and interatomic Coulomb interactions may be necessary for a proper description of the screening of the induced charge density: A. Vega and G.M. Pastor (unpublished).
23. The effects of the Cr matrix on the electronic structure of the Fe cluster are also evident by comparing the DOS of Fig. 4 with the corresponding results for free clusters given in Refs. onlinecitepdb1 and onlinecitevega1.

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