Network Former Mixing (NFM) Effects in Alkali Germanotellurite Glasses

摘要: Abstract Network former mixing (NFM) effects on ionic conductivities have been characterized in ternary germanotellurite glasses of composition (A2O)0.3[(TeO2)x(GeO2)1-x]0.7 (A = Li, Na), revealing an interesting cation dependence. While the results demonstrate a weak positive NFM effect Li-containing system, electrical Na-containing systems correspond to weighted average values observed their binary endmembers. The structural origins these differing explored by Raman scattering and 125Te solid-state NMR spectroscopy, indicating no significant differences organization materials. Overall, data suggest that concentration heteroatomic connectivities is relatively low. For analysis motional narrowing temperature-dependent static 7Li spectra confirms existence at local atomic level. Accordingly, absence for system corroborated low-temperature 23Na spin-echo decay showing very similar network modifier distributions those glasses.