Effect of Deuteration on the Electrical Conductivity, Dielectric Constant, and Phase Transition in (NH4)3H(SO4)2

Measurements of dc conductivity and dielectric constant show that deuteration causes an upward shift of the high tem­ perature phase b'ansition point from 186.5 to 191°C and a downward shift of the low temperature transition point from 10 to -1.5°C in LiNa.S04. Mechanisms of phase transitions and of electrical transport in the crystal are discussed.

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