INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Ab-initio calculations of FCC-FeMn alloys with the L10 crystallographic structure
J. MARTÍNEZ, J. DESIMONI, E. PELTZER Y BLANCÁ
Workshop; Quantum Theory of Solids 5; 2009
The antiferromagnetic FCC-phase of FeMn alloys has been the subject of numerous studies over recent decades [1-2]. Three magnetic structures, 1Q, 2Q and 3Q, based on the position and orientation of spins , have been proposed and studied. However, despite all the efforts of several theoretical and experimental works to determine unambiguously which one corresponds to the ground state, or at least to exclude some of them. These results always came up to contradictory conclusions, or confusing results, depending on the resolution of the experimental technique used [1, 3-4]. That is why there were attempts to resolve the problem through ab-initio calculations using the crystallographic structure L10 [5-7]. These calculations appear to overturn the balance in favor of the 3Q structure, however, this structure does not represent a completely random alloy, as is the case. Regarding that, the results of several variations of possible antiferromagnetic spins directions in the FeMn L10 structure are presented as a first step of calculations to the more complicated structure B21, which is closer to a random alloy. The calculations were performed with a full-potential linearized augmented-plane-wave code and the results obtained, with several types of exchange and correlation functional, were compared with reported experimental data. 1. H. Umebayashi and Y. Ishikawa, J. Phys. Soc. Jpn. 21 (1966) 1281. 2. F. J. Pinski, J. Staunton, B. L. Gyorffy, D. D. Johnson, and G. M. Stocks, Phys. Rev. Lett. 56, 2096 (1986). 3. S. J. Kennedy and T. J. Hicks J. Phys. F 17(1987) 1599. 4. P. Bianti, G. Mazzone, and F. Sacchetti, J. Phys. F 17, 1425 (1987). 5. C. Padduani, Mat. Scie, and Eng. B21 (2005) 9. 6. D. W. Bouklvahov, Y. N. Gornostyrev, M. I. Katsnelson and A. I. Lichtenstein, ariv:0706.3965v1 [cond-mat.mtrl-sci] 25 jun 2007. 7. C. Paduani and J. C. Krause, Phys. Rev. B 58 (1998) 175.