Article

Electronic and related properties of crystalline semiconducting iron disilicide

Belarusian State University of Informatics and Radioelectronics, P. Browka 6, 220027 Minsk, Belarus
Journal of Applied Physics (Impact Factor: 2.18). 06/1996; 79(10):7708 - 7712. DOI: 10.1063/1.362436
Source: IEEE Xplore

ABSTRACT

Band structure calculations for β‐FeSi 2 have been performed by the linear muffin‐tin orbital method within the local density approximation scheme including exchange and correlation effects. A detailed analysis of the conduction and valence band structure around high‐symmetry points has shown the existence of a quasidirect band gap structure in the material. It is experimentally confirmed that between the threshold energy of optical interband transition of 0.73 eV and the first direct gap transition with appreciable oscillator strength at about 0.87 eV there is a region in which direct transition of low oscillator strength and indirect transitions overlap. That explains the tricky behavior of β‐FeSi 2 in experimental investigations demonstrating it to be either a direct or indirect gap semiconductor. © 1996 American Institute of Physics.

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    • "However, our LMTO predictions on bandgap energies for other transitionmetal silicides provide larger values than those obtained by FLAPW and USPP. For example, the gaps of 0.02 and −0.03 eV were estimated by FLAPW [22] for hexagonal MoSi 2 and WSi 2 , respectively, to be compared to 0.07 eV of LMTO [23], and in the case of β-FeSi 2 the difference is found to be about 0.1 eV (see [24] [25] [26]). In order to confirm the last issue we have performed an additional calculation by USPP and FLAPW using the experimental lattice parameters and atomic positions, as in the case of [12], and revealing again the gapless character, that is in agreement with the LAPW results [13]. "
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