Electrical conductivity of silicate glasses with tetravalent cations substituting Si

Abstract

a b s t r a c tThe effects of substituting Si by M 4+ cations in soda-lime silica glasses were analyzed by impedance spectroscopy in the frequency range of 1 Hz-1 MHz. The glass composition was (mol%) 22Na 2 O·8CaO·65SiO 2 ·5MO 2 , M = Si, Ti, Ge, Zr, Sn, and Ce. Although the Na + concentration in the glasses is constant, the Zr-containing glass exhibits the highest dc conductivity and the lowest activation energy, while the Ce-containing glass exhibits the lowest conductivity. The activation energies obtained experimentally agree with those obtained by a theoretical equation proposed by Anderson and Stuart. The differences in electrical conductivity presented by the several M-containing glasses are attributed to the effect that the M 4+ ion has on the mobility of the diffusing Na + ion.

Comparison of activation energies for the electrical conductivity of silicate glasses obtained by dc and ac techniques

“…Glasses with composition (mol%) 22Na 2 O•8CaO•65SiO 2 •5MO 2 , M = Si, Ti, Ge, Zr, Sn, Ce, were obtained by melting appropriate quantities of sodium and calcium carbonates, quartz sand, and oxides of the other tetravalent cations, as previously reported [4]. The melting was performed in a platinum crucible at about 1450°C for 2 h, in an electric furnace.…”

Real‐time monitoring of crystal accumulation in the high‐level waste glass melters using an electrical conductivity method

“…Therefore, laboratory testing included temperatures spanning a range from 675 to 875°C. Conductivity of molten glass below T g (in the case of this glass, 490°C) has been found to be an exponential function with temperature 24,25 such that:…”

“…where n e is the effective charge carrier concentration, e is the charge for the single charge species, and μ is its electrical mobility . At temperatures below the glass transition temperature ( T g ), these glasses follow a temperature‐activated mechanism represented by the Arrhenius law and a free‐volume mechanism described by Cohen and Turnbull that assumes random density fluctuations create “free” volume allowing for molecular transport .…”

“…where n e is the effective charge carrier concentration, e is the charge for the single charge species, and l is its electrical mobility. 9 At temperatures below the glass transition temperature (T g ), these glasses follow a temperature-activated mechanism represented by the Arrhenius law and a free-volume mechanism described by Cohen and Turnbull 10 that assumes random density fluctuations create "free" volume allowing for molecular transport. 11 Electrical conduction in silicate glasses is further dependent on the concentration of cations and their bond strength to the network where Na + -BO À 4 bonds with bridging oxygen transform into Na + -BO 2 O À bonds with nonbridging oxygen.…”

Microestrutura, fases cristalinas e propriedades elétricas de porcelanas aluminosas contendo diferentes concentrações de Fe2O3sinterizadas em atmosfera redutora e oxidante

“…A fase vítrea também possui a mesma dependência com a temperatura. Originada a partir da fusão de feldspatos, a fase vítrea possui grande concentração de cátions (Na + e K + ), que com o aumento da temperatura, promovem um aumento na condutividade elétrica [32].…”