HARD-SPHERE MODEL OF ACTIVATION-ENERGY ORIGINATED IN ION SIZE - GATE MODEL

The gate model is proposed such that a mobile ion happens to hop between adjacent sites only when immobile (gate) ions probabilistically move away to keep an enough space: By taking account of hard-sphere ions vibrating around their stable sites, the transition probability rate-GAMMA is statistical-mechanically evaluated according to the Vineyard method. The obtained GAMMA is of activation-type where the activation energy increases with the overlap length defined with radii of mobile and immobile ions, and also increases with the gate frequency.