Some diluted magnetic semiconductors (DMS), in which magnetic elements are substituted for a small fraction (~5%) of host elements in a semiconductor lattice, show ferromagnetism, and thus possess potential applicability in spintronics. To obtain quantum-mechanical understanding of electronic and spin structure, we have performed ab initio total energy calculations on IV:TM (IV=SiC, Si, Ge, TM=V, Cr, Mn, Fe, Co, Ni). We used the generalized gradient approximation (GGA) to describe the exchange-correlation interaction between the electrons, and incorporated the projector augmented wave (PAW) potential to simulate the electron-ion interaction. The stability of the ferromagnetic phase in SiC-, Si-, and Ge-based DMS is investigated comprehensively. From the energetics, we found that IV:TM reveals ferromagnetism for the case of V, Cr, Mn, and Fe. The origin of the magnetism will be discussed in terms of the density of states and the wave function characters around the Fermi level.
Journal: TechConnect Briefs
Volume: 3, Technical Proceedings of the 2003 Nanotechnology Conference and Trade Show, Volume 3
Published: February 23, 2003
Pages: 519 - 521
Industry sector: Advanced Materials & Manufacturing
Topics: Nanoparticle Synthesis & Applications