Ionic Conduction in Glasses

Abstract

The activation energy of ionic conductivity in a variety of glasses has been studied from a unified point of view. A plot of the activation energy as a function of the cation–anion distance manifests that the glass can be divided into two groups; the examples being chalcogenide and oxide glasses. In the chalcogenide the activation energy becomes smaller with the increase in the cation–anion distance, while in the oxide the opposite trend exists. Origins of these features are discussed in connection with carrier and mobility activations.

Bond character, optical properties and ionic conductivity of Li2O/B2O3/SiO2/Al2O3 glass: Effect of structural substitution of Li2O for LiCl

“…Accordingly a considerable increase in the ionic conductivity in case of LiCl is expected. Taking the cation-anion distance approach into account, it has been found that in the oxide glasses the activation energy of the ion conduction becomes smaller with the decrease in the cationanion distance, while in chalcogenide glasses the opposite trend exists [45]. Thus decrease the cation-anion in oxide glasses increases the ionic conductivity.…”

Conductive bridging random access memory—materials, devices and applications

“…To understand how ions move in these materials, the best example is perhaps that of metal-doped chalcogenide glasses. In these, the metal ions (M + ) are associated with nonbridging chalcogens (Ch − ) but the M-Ch bonds are quite long, e.g., around 0.25 nm in Ag-Ge-S ternaries [69]. The coulombic energy is inversely proportional to the (fixed) anion-(mobile) cation separation and so these long bonds result in small attractive forces, <0.5 eV (assuming a dielectric constant in excess of 10 which is reasonable for these materials), making it relatively easy to dislocate the metal cations.…”

Medium range order in oxide and chalcogenide superionic glasses: A comparative study by using the average electronegativity

“…It is however, difficult to understand straightforwardly why the activation energy of different glasses varies systematically with the FSDP wave number, because the activation energy is expected to be determined mainly by short range interatomic interactions [7]. In relation with this point, it is worth noting the interesting observation that in chalcogenide glasses the activation energy of ion conduction becomes smaller with the increase in the cation-anion distance, while in the oxide glasses the opposite trend exists [12].…”

“…2 we recognize that the trend in FSDP wave number that results by the addition of Ag 2 S or CuI in chalcogenide network former GeS 2 or As 2 S 3 , is different from the oxide systems (B 2 O 3 fi Ag 2 O-B 2 O 3 , Li 2 O-2B 2 O 3 , etc.). This difference in behavior is not surprising, because the properties of oxide and chalcogenide glasses differ in many aspects [12,21]. This observation indicates that v m alone cannot take into account all these material differences.…”