DECONVOLUTION OF PYRITE MARCASITE AND ARSENOPYRITE XPS SPECTRA USING THE MAXIMUM-ENTROPY METHOD

The maximum entropy method (MEM) is a new procedure for deconvoluting exciting line width and instrument resolution contributions From XPS s pectra. MEM has been used to obtain additional detail front XPS 2p spe ctra collected from pyrite. marcasite and arsenopyrite surfaces which have been exposed by fracturing under UHV conditions. The resultant sp ectra have line widths that are nearly 50% narrower than the original spectra. Deconvoluted S 2p and Fe 2p(3,2) spectra are shown to contain contributions from species located in disrupted lattice sites near th e fracture surface as well as species on the outermost fracture surfac e. Iron 2p spectra are also found to exhibit fine structure which is a ttributed to multiplet splitting. (C) 1998 Elsevier Science B.V.