Electrical conduction and diffusion studies of some hydrogen bonded crystals

• Main Author: Sharan, Maheshwar
• Published: University of Leicester 1967
• Subjects: 540
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.737067

A method has been developed for studying proton conduction in solids( KHK2 , KHaPO 4,NH4 PO4 , KH2, AsO4 , and Oxali acid dihydrate ),in which, hydrogen gas evolved on d.c, electrolysis of the solid, is collected and measured. These conductions have shown to be entirely protonic in nature. The conductances of the solids mentioned above have also been measured as a function of the temperatur by an A.C. method. The activation energies obtained experimentally have been interpreted in terms of the formation of proton defects in the crystal. Comparisons have been made between activation energies obtained for polycrystalline samples, and single crystals. The effect of crystal orientation on the activation energy has also been investigated in the case of NH4H2,PO4 and KH2P04. It is concluded that conductance data on single crystals are preferable to compressed pellets, provided the direction of measurement is specified. The measurements on the H-bonded crystals have been repeated for the corresponding deuterated compounds and a comparison is made between them. A tritium diffusion has been studied on a single crystal of NH4H2PO4.It has been concluded that the ''Einstein Relation" is obeyed; i.e., conduction and diffusion occur by the same mechanism.