Synthesis and characterization of potassium, rubidium, and cesium thiogermanate glasses

Glass formation in and structural investigation of Li2S+GeS2+GeO2 composition using Raman and IR spectroscopy

“…This is in agreement with the T g behavior of previously reported alkali (Li, Na, Rb, K, and Cs) thio-germanates [18,27]. An increase of alkali modifier content increases the number of non-bridging sulfurs and creates a more broken-up network structure and thus causes structural relaxation to occur at lower temperatures.…”

Structure and properties of glasses in the MI+M2S+(0.1Ga2S3+0.9GeS2), M=Li, Na, K and Cs, system

“…This peak has been previously attributed to the symmetric Ge-S-Ge bridgebending mode due to the creation of Ge 4 S 4À 10 adamantinelike structures, shown in Fig. 1 [9], and found in the heavier alkali, Rb and Cs glasses.…”

“…However, in the heavier alkali M = K, Cs, xM 2 S + (1 À x)(0.1Ga 2 S 3 + 0.9GeS 2 ), where x = 0.3 and 0.4 glasses, the peak at $200 cm À1 appears in Raman spectra suggesting the formation of Ge 4 S 4À 10 structures in these glasses. There is no such peak in the Raman spectra of low alkali content xM 2 S + (1 À x)GeS 2 glasses , 0 6 x 6 0.2, M = K, Cs [9]. With further addition of K 2 S and Cs 2 S, x = 0.27 and 0.33, the compositions are not glass forming and suggests the poly-crystal is the preferred form.…”

“…Likewise, for the K 2 S and Cs 2 S system, the glass forming range extends to x = $0.4 compared to x = $0.2 in the GeS 2 binary system. Although low alkali sulfide content compositions were not explored in this study (due to their expected low alkali ion conductivity), it is expected that they should also yield glasses according to studies of the previous binary systems [9].…”

“…It is found that the Na 2 S + GeS 2 system has the largest glass forming region from 0 to $0.6 mole fraction of Na 2 S, while both the Li 2 S + GeS 2 and Ag 2 S + GeS 2 systems have glass forming regions from 0 to $0.5 mole fraction. Recently, the heavy alkali binary systems of M 2 S + GeS 2 , M = K, Cs, and Rb, have been investigated for the first time where a novel alkali sulfide preparation route was used [9]. However, the M 2 S + GeS 2 , M = K, Cs, Rb, systems were found to have limited glass forming ranges only between 0 and 0.2 mole fraction.…”