Dresden 2003 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Magnetismus
MA 7: Spin-Elektronik
MA 7.7: Vortrag
Montag, 24. März 2003, 16:45–17:00, HSZ/401
Atomic, electronic, and magnetic structures of Mn/Si(100) films – a first-principles study — •Hua Wu, Mahbube Hortamani, Peter Kratzer, and Matthias Scheffler — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
As the lattice mismatch of ferromagnetic (FM) fcc Mn and Si(100) is small (about 3%), a Mn/Si(100) film is an interesting spintronics candidate. Using density-functional theory and the full-potential APW method, we have studied the atomic/electronic/magnetic structures of thin pseudomorphic Mn/Si(100) films by a slab model.
For monolayer (ML) Mn on both sides of 8 Si(100) layers, the 1×1 structure (A) with a bridge Mn is more stable than that (B) with an atop Mn by about 1.0 eV/uc (unit cell) total energy (Et) lowering for each of the nonmagnetic (NM), FM, and antiferromagnetic (AFM) states. Morevoer, the AFM state has a lower Et than the FM one by 0.39 (0.38) eV/uc for A (B), and the NM state (with about 4.0 eV higher Et) is unstable. All these solutions are metallic mainly due to itinerant Mn 3d electrons and Mn 3d-Si 3p covalent couplings. The Mn spin moment is significantly increased from 1.95 µB in the fcc AFM bulk phase to 3.3-4.0 µB in the ML. As for 1ML MnSi alloy on Si(100), the FM metallic state has a little lower Et than the AFM state by 0.07 eV/uc. For 2ML-Mn/Si(100), a relatively stable layered AFM state is found.
Proceeding calculations: [1] the absorption energy of Mn in the small coverage limit, [2] simulation of initial growth of thin Mn films on Si(100), and [3] a search of FM half-metallic Mn/Si(100) films.