Full potential calculations on the electron bandstructures of Sphalerite, Pyrite and Chalcopyrite

The oxidation states of copper and iron in mineral sulfides, and the oxides formed on initial exposure of chalcopyrite and bornite to air

“…5b that the broader Cu L 3 peak situated $5 eV above the leading absorption peak would arise from transitions to Cu s-states and, to a lesser extent, Cu d-states. Most of the previous electronic structure calculations for chalcopyrite, including those using FEFF8 with the Hedin-Lundqvist exchange potential (Lavrentyev et al, 2004), are in broad agreement with the FEFF8 calculations carried out in the present study (Hamajima et al, 1981;Tossell et al, 1982;Petiau et al, 1988;Kurmaev et al, 1998;Edelbro et al, 2003).…”

Copper oxidation state in chalcopyrite: Mixed Cu d9 and d10 characteristics

“…Since the satellite intensity is very low for monovalent compounds, the d-count is not specified in this case in Table 1. The fact that the d-count is always quite far from d 10 is due to the covalent character of the compounds as confirmed by the results of bandstructure calculations (Hamajima et al, 1981;Kurmaev et al, 1998;Edelbro et al, 2003). For instance, the calculation by Hamajima et al (1981) quotes values for Cu in CuFeS 2 of n d = 9.63, n 4s = 0.54 and n 4p = 0.76.…”

“…Recommended calibration values are 931.2 eV for the Cu L 3 peak in CuO and 707.7 eV for the Fe L 3 peak in Fe metal. All theoretical and experimental investigations recognise the covalent character of chalcopyrite which involves extensive overlapping of Cu and Fe metal d orbitals across the whole valence band (Tossell et al, 1982;Kurmaev et al, 1998;Edelbro et al, 2003).…”

Thermodynamics of monochlorophenol isomers and pyrite interfacial interactions in the activation state

“…It is an intrinsic semiconductor that exhibits both n-and p-type conductivity [7,8]. The band gap is around 1 eV thus it can efficiently be used as a photocatalyst in the destruction of both organic and inorganic pollutants [8,9]. Very recent evidence suggests that the defect sites of pyrite are capable of splitting H 2 O to form reactive OH radicals (the key for chemical oxidation of organic pollutants) in the absence of light [10].…”