The effect of the partial substitution of sulfur on the structural and microstructural properties of selenium

Abstract

Samples of amorphous Se, SSe40, SSe30, and SSe20 were synthesized and were then crystallized by annealing at 373 K for 5, 20, and 120 mins. The results showed that the changes in the structural and microstructural parameters for samples SSe40, and SSe30 are different from those of sample SSe20. These discrepancies are being discussed in terms of the peak shifts in both the amorphous and crystalline state, the percentage of sulfur compositional variations, and finally in terms of the probable site occupancy of the sulfur atoms in the selenium structure.

Vibrational, optical and structural studies of an amorphous Se0.90S0.10alloy produced by mechanical alloying

“…where E g is the band gap and ν is the frequency of the incident beam. The analysis consists of fitting the absorption edge to (9) and determining experimental values for E g and n. n = 2 corresponds to a direct allowed transition. n = 2 3 implies a direct forbidden transition.…”

The elimination of selenium(IV) from aqueous solution by precipitation with sodium sulfide

“…Since sulfur and selenium are miscible in all proportions and can form polymer-like molecules of crystalline or amorphous composition, it appears that the sulfur-selenium solid solutions are composed of cyclic Se-S rings containing a variable number of Se and S atoms, most commonly following the general formula Se n S 8−n [27][28][29]. These cyclic molecules have been extensively studied and three different phases (that depend on the sulfur to selenium ratio) have been shown to exist [30].…”

Reverse Monte Carlo simulations of an amorphous Se0.90S0.10 alloy produced by mechanical alloying combining XRD and EXAFS data

“…Kotkata et al [8,9], produced several amorphous and crystalline Se x S 1 − x alloys and obtained some general results from XRD measurements indicating that amorphous alloys can be prepared in a relatively wide compositional range, from x=0.5 to x=1, the density of the alloys decreases as the S content is increased and the average total coordination number for Se atoms (〈N Se 〉=〈N Se − Se 〉+ 〈N Se − S 〉) is 2. Heiba et al [10] also used the XRD technique to study the crystallization of Se x S alloys, x=20,30,40, and crystallite sizes were determined from a refinement using the program FULLPROOF. A more detailed investigation of amorphous alloys was made by Shama [11], which reports the results obtained from simulations of the first shell of the RDF determined for three amorphous Se x S alloys, x=10,30, 40.…”