Journal of Magnetism and Magnetic Materials 304 (2006) e146–e148 Magnetic and electronic structures of zinc-blende FeX (X ¼ P, As, Sb) by first principles calculations Gul Rahman, Sunglae Cho, Soon Cheol Hong à Department of Physics, University of Ulsan, Ulsan 680-749, Republic of Korea Available online 28 February 2006 Abstract Magnetic and electronic structure calculations are carried out for hypothetical zinc-blende (zb) phase of FeX (X ¼ P, As, Sb) by using the full-potential linearized augmented plane wave (FLAPW) method. For zb FeSb, the total energy has been calculated as a function of lattice constant in ferromagnetic (FM) and antiferromagnetic (AFM) states. We found that the ground state of zb FeSb is very stable with respect to compression and expansion of the unit cell. The magnetic moment of zb FeSb in the AFM state is increasing with the lattice constant. The magnetic and electronic structures calculations of FeAs (FeP) are carried out for the lattice constants of GaAs (GaP), InAs (InP), and Si. Our finding shows that AFM is the ground state for all of our calculated zb FeX compounds and do not belong to the class of zb half metallic ferromagnets. r 2006 Elsevier B.V. All rights reserved. PACS: 75.90.+w; 71.20.b; 71.20.Be Keywords: Zinc-blende; Electronic band structure; Antiferromagnetism The swiftly developing field of spin electronics has provided strong motivation towards the synthesis of novel magnetic materials. Of particular interest are half metallic ferromagnetic (FM) materials. These materials, in which one of the two spin channels is metallic while the other has an energy gap at the Fermi energy, have attracted increasing research interest because of their potential in spintronic applications. Many of them have been predicted theoretically [1,2] and then fabricated experimentally [3] using molecular beam epitaxy (MBE). A few zb structure materials [4,5] show antiferromagnetic (AFM) behavior, while zb FeN does not show any magnetism [6]. FeP and FeAs have MnP-type (B31) structure in nature. The band structures of FeAs with orthorhombic MnP (B31) and closely related hexagonal NiAs (B8 1 ) structures have been calculated by Podloucky [7]. The natural stoichiometric FeSb does not exist as in a single phase, and alloys quenched from 800 1C show NiAs structure [8]. In this paper, FeX (X ¼ P, As, Sb) compounds in zinc- blende (zb) structure are investigated theoretically to find whether the FeX compounds have half metallic FM or the other magnetic structures. We calculated the total energies, magnetic moments, and density of states (DOS) of FeX. The lattice constants of InP (5.86 A ˚ ), GaP (5.451 A ˚ ), and Si (5.431 A ˚ ) are used for FeP, and those of InAs (6.05 A ˚ ), GaAs (5.65 A ˚ ), and Si are used for FeAs to see the effect of different lattice constants on magnetic and electronic structures of these compounds. The equilibrium lattice constant of FeSb is determined from the total energy calculations. We employed the spin-polarized, full-potential linearized augmented plane wave (FLAPW) method [9] based on density functional theory in generalized gradient approx- imation (GGA) [10]. The core electrons are treated fully relativistically, whereas the valence electrons are treated semirelativistically. The basis functions are expanded in terms of the spherical harmonics upto l ¼ 8 inside each muffin-tin sphere and described as plane-waves in the interstitial region. The muffin-tin radii are chosen as 2.20 a.u. for Fe, Sb, As, and P. ARTICLE IN PRESS www.elsevier.com/locate/jmmm 0304-8853/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.jmmm.2006.02.037 à Corresponding author. Tel.: +82 52 259 2331; fax: +82 52 259 1693. E-mail address: schong@mail.ulsan.ac.kr (S. Cheol Hong).