1H NMR and conductivity studies of protonic conductors HSbO3·nH2O and SnO2·nH2O

Abstract ac conductivity measurements are reported for various hydrated samples of antimonic acid HSbO 3 · n H 2 O and stannic acid SnO 2 · n H 2 O. Data reveals that water content dependence of the conductivity is close for both materials, involving similar activation energies. 1 H NMR relaxation times T 1 , T 1 ρ 1 , T 2 are reported for the same hydrated compounds, in the temperature range 160 K T 3 · n H 2 O, fast proton exchanges occur between all the various protonated species whatever the water composition. In SnO 2 · n H 2 O, results show that dehydration process induces a change of the protonated species ratio. Heterogeneous environment prevents exchange between all the species and very complicated NMR behaviour is shown.