Electronic structure, optical and X‐ray emission spectra in FeS₂

Abstract

The electronic structure, optical spectra, X‐ray emission (XE) and X‐ray absorption (XA) spectra of FeS2 were investigated theoretically from first principles, using the fully relativistic Dirac LMTO band structure method in local density approximation (LDA). Theory produces correct semiconductor ground state in FeS2 with the energy gap of Eg = 0.9 eV in good agreement with the experimental data. Densities of valence states are analyzed and discussed. The origin of the optical, XA and XE spectra in the FeS2 compound is examined. The calculated results are compared with available experimental data. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Pseudodielectric function and critical-point energies of iron pyrite

“…Two prominent CP features are evident in the SE data at ~2.0 eV and ~4.0 eV, as also observed in early studies. [8][9][10][11][12][13] Although the calculations slightly overestimate the CP energies below 3 eV and underestimate those above it, the overall agreement between experimental and theoretical results is obvious. All six of the major CP features observed experimentally are captured in the DFT calculations.…”

Investigation of Photocarrier Losses in Pyrite (FeS2) Film Consisting Single Crystal Nanocubes

“…A possible optical transition at 1.5 eV corresponds to the fundamental direct band to band excitation, consistent with previously reported values [31,32]. The third probable transition could be obtained at 1.9 eV agrees well with values approximated by theoretical study and experimentation and could be attributed to the interband excitonic transition [22,33,34]. Notably, the discrepancies in commonly reported optical band gap of pyrite could be an indication of the presence of fuzzy band edges in pyrite, a common feature in disordered semiconductors.…”

First-principles calculations of sulphur isotope fractionation in MX2 minerals, with M= Fe, Co, Ni and X2= AsS, SbS

“…The structures of the sulphides are quite complex because of the bonding characteristics (Zoltai and Stout, 1984). Most of the bonding in the sulphide minerals is covalent or metallic or both (Berry et al, 1983;Zoltai and Stout, 1984); the nature of the bonding has long been controversial (Antonov et al, 2009;Birkholz and Rudert, 2008;Brostigen and Kjekshus, 1970;Cervantes et al, 2002;Finklea et al, 1976;Hulliger and Mooser, 1965;Pauling, 1978;Pauling and Huggins, 1934;Schmøkel et al, 2014;Sithole et al, 2003;Sourisseau et al, 1991). In disulphides, sulpharsenides and sulphantimonides, not only can the S atom form metal-sulphur bonding with the metal atom, but it can also form metalloid-sulphur bonding with the metalloid atom (e.g., S, As and Sb atoms).…”