Test of Anderson-Stuart model in sodium silicate glasses and the general Arrhenian conductivity rule in wide composition range

Abstract

We collected and analyzed literature data on ionic conductivity sigma and activation energy E A in the binary sodium silicate system in a wide composition range. The Anderson and Stuart model has been considered to describe the decreasing tendency of activation energy E A with alkali concentration in this system. In this analysis were considered experimental parameters, such as shear modulus G and relative dielectric permittivity epsilon. A general conductivity rule is found in 194 of 205 glasses, when one plots log sigma vs. E A/kB T, where kB is the Boltzmann constant and T is the absolute temperature. This fact means that the arrhenian relation has universal uniqueness of form sigma = sigma (E A,T) in wide Na2O composition range. The results also show that there is strong correlation by more than 19 orders of magnitude on conductivity with E A/kBT. An explanation for this behavior links ionic conductivity and microscopic structure. The problem of phase separation in this system is also considered.

Revealing the fast atomic motion of network glasses

“…2a are very close to that reported in literature for the sodium diffusion. The latter however corresponds to relaxation times many orders of magnitude faster than those observed here [56][57][58] . This is shown in Fig.…”

Test of the Anderson–Stuart model and correlation between free volume and the ‘universal’ conductivity in potassium silicate glasses

“…Nascimento and Watanabe [42][43][44][45][46] have recently verified this 'universal' finding in binary silicate, borate and germanate glasses, considering both Eqs. (1) and (7).…”

“…Another "universal" curve, following Eq. 7and considering some binary silicate, borate and germanate glasses, resulted in the same 'universal' behaviour [42][43][44][45][46], as cited above. The pre-exponential value was σ 0 = 50, 000 K −1 cm −1 .…”

Influence of the various doping elements on the microwave dielectric loss of silica

“…However in this work, it is presumed that there is no significant influence by very small quantities of impurities on the shear modulus of silica glass; thus, G 0 , in this instance, is 3.1 GPa. The researcher Nascimento [25] reported that r D0 (at 300 K) versus composition varied in a range, i.e., 0.37Å < r D0 < 0.72Å. Therefore, for small amounts of doping, it can be deduced that the value of r D0 is approximately 0.37Å.…”

“…where 0 is 3.82, d /dn is 0.1681 ± 0.0029/mole% [25] and d /dT = 3.6 × 10 −4 /K [26]. Thus, the temperature dependence of the activation energy is expressed as:…”