First-principles studies of the electronic and dynamical properties of monosilicides MSi (M = Fe, Ru, Os)Y. N. Zhao1, H. L. Han2, Y. Yu1, W. H. Xue1 and T. Gao1
1 Institute of Atomic and Molecular Physics, Sichuan University - Chengdu 610065, PRC
2 College of Mathematics, Sichuan University - Chengdu 610064, PRC
received 7 November 2008; accepted in final form 19 January 2009; published February 2009
published online 4 March 2009
We study the electronic band structure, dielectric, and lattice dynamical properties of FeSi, RuSi and OsSi from first principles using density functional theory. We performed the band structure calculations for these compounds to confirm they are indirect band-gap semiconductors. Density functional perturbation theory is employed to evaluate the Born effective charge tensors, the dielectric permittivity tensors, the phonon frequencies at the -point, and the phonon dispersion curves as well as the corresponding density of states. These calculated results are in reasonable agreement with the experimental data and theoretical values available. From the present calculation we also predict that there exist longitudinal-transverse optical (LO-TO) splittings by 2–32 cm-1 for these three compounds, which were not observed in previous experiments.
71.15.Mb - Density functional theory, local density approximation, gradient and other corrections.
71.20.-b - Electron density of states and band structure of crystalline solids.
71.20.Nr - Semiconductor compounds.
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