EXAFS and cumulant expansion studies of an amorphous Se90P10 alloy produced by mechanical alloying

Structural, vibrational and optical studies on an amorphous Se90P10alloy produced by mechanical alloying

“…Besides this, it is interesting to note that the structures of LQ and MA samples are very different, since in LQ samples the mode on 145 cm −1 is not seen (see figure 3 of [5]), in agreement with Itoh et al [10]. To obtain more information about the structure of the alloy, we investigated it through EXAFS analysis and cumulant expansion (see [22]), and also using RMC simulations, which are discussed below.…”

“…In that study, only qualitative results were obtained and, since alloys produced by MA and by LQ can show relevant structural differences [11][12][13][14][15][16][17][18][19], we started a detailed investigation on the structure and other physical properties of Se 100−x P x alloys produced by MA. Recently, considering EXAFS measurements on Se K edge at five temperatures and the cumulant expansion method [20,21,16], we obtained relevant information related to structural properties of an amorphous Se 90 P 10 alloy (a-Se 90 P 10 ), including Se-Se and Se-P average interatomic distances and coordination numbers, structural and thermal disorder and asymmetries of the g Se−Se (r) and g Se−P (r) functions [22]. However, since we had EXAFS data only on the Se K edge, it was not possible to obtain data about P-P pairs or about the structural units present in the alloy.…”

Structural investigations on an amorphous Se90Te10alloy produced by mechanical alloying using EXAFS, cumulant expansion and RMC simulations

“…Some structural data obtained from the cumulant analysis are seen in table 1. The average coordination numbers for Se-Se and Se-Te pairs are similar to those found for alloys with similar stoichiometries, such as Se 90 S 10 [62,13] and Se 90 P 10 [63,64]. They also agree with the values obtained by Itoh et al [65] and Majid et al [47] for similar compositions.…”

Structural and thermal investigations of an amorphous GaSe9 alloy using EXAFS, cumulant expansion, and reverse Monte Carlo simulations

“…This result is different from those found for other Se-based alloys, where the heteropolar pair is stronger than the Se-Se pair. For comparison, Kostrzepa et al 70 obtained k E e,Se-Se = 9.2 eV/Å 2 and k E e,Se-Te = 18.2 eV/Å 2 , for a-Se 90 Te 10 , Machado et al 74 found k E e,Se-Se = 10.6 eV/Å 2 and k E e,Se-P = 13 eV/Å 2 , for a-Se 90 P 10 , and, for a-InSe 9 , Machado et al 75 obtained k E e,Se-Se = 7.6 eV/Å 2 and k E e,Se-In = 8.6 eV/Å 2 . The average interatomic distances, that correspond to the first cumulant C 1 , can be seen at Fig.…”