The temperature and humidity dependences of the conductivity were investigated for 2 types of antimonic acid; one with a cubic structure, and one with a monoclinic structure. It was found that the conductivity of the monoclinic form at 296K was lower, and more sensitive to humidity, than was that of the cubic form. The conductivity of the latter increased with increasing temperature, while that of the monoclinic form decreased with increasing temperature (for a saturated water vapor pressure and temperatures of between 296 and 353K). Other measurements revealed the existence of motion-restricted H2O in the monoclinic material. The amount of adsorbed water in the cubic material was greater than that in the monoclinic material. It was concluded that the difference in conductivity of the 2 forms was closely related to the state of the hydroxyl groups and H2O molecules.

T.Uchikoshi, Y.Sakka, M.Amano: Solid State Ionics, 1996, 89[3-4], 351-4