DEFECT-INDUCED SMOOTHING OF THE SUPERIONIC PHASE-TRANSITION IN CS1-XMXHSO4 PROTONIC CONDUCTORS .2. LITHIUM SUBSTITUTION

The preparation of Cs(1-x)Li(x)HSO4 (x less-than-or-equal-to 0.5) crystals allows study of the influence of host lattice defects on the superionic protonic conductivity. The superionic (SI) phase transition disappears at the first constriction of the unit cell parameter (x greater-than-or-equal-to 0.1) and electrical properties in the high and low-temperature range are brought together. With large amount of lithium the hydrogen bond remains constant in a wide temperature range whereas the Li+ disorder increases regularly. A premelting phenomenon is observed above 400 K, i.e. above the temperature of the SI phase transition in pure CsHSO4.