Structural and kinetic evaluation of Sn–Sb–Se alloys

Abstract

SnxSb20Se80−x chalcogenide alloys (with x = 8, 10, 12, 13.5, 15, 16.5 and 18 at.%) were prepared by the melt quenching technique. The average coordination number and the overall mean bonding energy were calculated. The x-ray diffraction studies revealed that the alloys with x = 8 and 10 at.% were amorphous and the alloy with x = 12 at.% was partially crystalline whereas the alloys with x = 13.5, 15, 16.5 and 18 at.% were crystalline. The glass transition temperature, the crystallization temperature, the melting temperature and the glass-forming tendency of the amorphous samples were determined from the differential scanning calorimetry measurements. The glass transition activation energies and the crystallization activation energies were determined using Kissinger as well as Augis and Bennett methods. Upon annealing the bulk amorphous samples at 573 K, two different crystalline phases, SnSe2 and Sb2Se3, were observed. X-ray reflectometry analysis revealed that the surface roughness increased with increasing annealing temperature. The density of the as-prepared films increased with increasing Sn content. Upon annealing at 523 K the density increased, whereas the density of most of the films decreased upon annealing at 573 K. Thermal gravimetric analysis showed a steeper weight loss upon heating after 533 K.

Experimental investigation on some electrical parameters of In10−Sn Se90 (x = 2, 4, 6, and 8) chalcogenide glasses before and after γ-irradiation

“…This decreases the average single bond energy of the glasses which in turn increases the cohesive energy and is responsible for the corresponding increase in the conductivity of the glasses up to 6 at.% of Sn. However, the decrease in the conductivity at 8 at.% of Sn may be attributed to readjustment in the local environment which involves the formation of SnSe 4/2 tetrahedral with coordination number of Sn ¼ 4 [40,41] rather than 6. This makes the average coordination number of In 2 Sn 8 Se 90 equal to 2.22 rather than 2.38 [32] which increases the average single bond energy of this composition and hence decreases its conductivity.…”

“…E s is the corresponding activation energy, which for conduction in the extended states, represents the energy difference between mobility edge and Fermi level (E c À E F ) or (E F À E v ) for conduction in the localized states [33]. E s is usually approximately half of the optical band gap E g indicating that the Fermi level lies near the mid-gap (E g z 2E s ) [41]. The values of E s for un-irradiated and irradiated samples can be calculated from the slopes of the linear fits of ln (s) against 1/T in the high-temperature region (250e290 K).…”

Microhardness and optical property of chalcogenide glasses and glass‐ceramics of the Sn–Sb–Se ternary system

“…Using the Gaussian decomposition method as shown in Figure C,D, each Raman spectrum was converted into four overlapped Gaussian peaks at 178, 190, 211, and 252 cm −1 , which corresponded to the vibration of tetrahedral SnSe 4 and pyramidal SbSe 3 , as well as the bending and stretching of Se 8 rings, respectively. The normalized integrated area ( A nor ) of all decomposed peaks was also calculated for quantitative analysis.…”

Electrical and optical properties of Sn10Sb20−xBixSe70 (0⩽x⩽8) glassy films

“…They also found that the band gap decreases with the incorporation of a small amount of Bi while it remained nearly constant with further increase in Bi content, indicating that the conduction type was controlled independently of the band gap change. From the parent glass system, we have chosen Sn-Sb-Se glass, as it is a good glass former, with better thermal, electrical and optical properties [6,7]. The role of Bi incorporation on the electrical and optical properties in this system has not been studied until now.…”