THEORY OF PROTON-INDUCED SUPERIONIC CONDUCTION IN HYDROGEN-BONDED SYSTEMS

This paper consists of three sections. After the Introduction of Section 1, in Section 2 we describe a quantum mechanical mechanism of proton-induced ionic conduction in the superionic phase in zero-dimensional hydrogen-bonded M(3)H(XO(4))(2) (M=K,Rb,Cs, X=S,Se] materials, by giving a review on the theory developed by Ito and Kamimura. Then we discuss the characteristic difference between quantum mechanical and classical mechanisms in the case of proton-induced superionic conducction, in paticular, by comparing characteristic time scales in quantum mechanical and classical diffusions in hydrogen-bonded systems. In Section 3 a theory is proposed with regard to the origin of the divergent behavior of ionic conductivity near the phase-transition temperature in the ferroelatic phase of M(3)H(XO(4))(2).