Determination of Mobility and Charge Carriers Concentration from Ionic Conductivity in Sodium Germanate Glasses above and below 𝑇_𝑔

Table 1

Numerical resulting values from the fits of conductivity to (9) at low temperature, to (23) for high temperature, and viscosity data to (5), considering 𝐴_𝜂=10⁻⁵Pa⋅s [8]. Please note that we used the same 𝑇₀ in conductivity as well as viscous flow processes above 𝑇_𝑔.

(a) 𝑇<𝑇_𝑔

xNa2O	𝐴^low𝜎 (K/Ω · cm)	Δ𝐻𝑓 (eV)	Δ𝐻𝑚 (eV)	𝐸^𝐴𝜎 (eV)
0.05	10^4.616±0.049	1.7850±0.0024	0.1817±0.0006	1.0742±0.0055
0.10	10^5.66±0.69	1.9023±0.0015	0.1828±0.0012	1.134±0.081
0.15	10^5.08±0.23	1.6597±0.0011	0.1791±0.0041	1.009±0.027
0.20	10^5.044±0.046	1.4778±0.0024	0.1771±0.0008	0.9160±0.0055
0.25	10^5.63±0.27	1.3796±0.0038	0.1767±0.0031	0.866±0.030
0.296	10^5.05±0.21	1.0955±0.0097	0.1742±0.0023	0.722±0.023

(b) 𝑇>𝑇_𝑔

xNa2O	𝐴^high𝜎 (K/Ω · cm)	𝐸^𝐴𝜎=Δ𝐻𝑓/2  (eV)	𝐵𝜎 (eV)	𝐸^𝐴𝜂 (eV)	𝐵𝜂 (eV)	𝑇0 (K)	𝑇𝑔 (K)
0.05	10^4.616±0.049	0.8925±0.0012	0.0180±0.0097	1.189±0.049	0.231±0.012	580±10	729
0.10	10^5.66±0.69	0.9512±0.0008	0.0139±0.0040	1.082±0.091	0.190±0.024	669±21	783
0.15	10^5.08±0.23	0.8299±0.0005	0.0181±0.0098	1.081±0.057	0.177±0.017	706±4	791
0.20	10^5.044±0.046	0.7389±0.0012	0.0129±0.0097	0.977±0.011	0.209±0.014	693±5	793
0.25	10^5.63±0.27	0.6898±0.0016	0.0299±0.0034	0.889±0.006	0.2655±0.0024	624±19	755
0.296	10^5.05±0.21	0.5478±0.0048	0.0176±0.0057	0.712±0.091	0.2887±0.0061	599±6	716