NUCLEAR MAGNETIC RESONANCE STUDY OF LITIUUM SULPHATE BASED SOLID ELECTROLYTES

Abstract

The main purpose of this dissertation is for pulsed nuclear magnetic resonance study and investigation of lithium sulphate and its solid solutions which exhibit fast ion conductivities. In the monoclinic phase Lithium sulphate "Anhydrous" has been studied using NMR technique .The spin lattice and spin-spin relaxation times has been measured at different temperatures between 298K and 825 K at frequencies 12.37 and 21 MHz

In the cubic phase measurements of the spin lattice relaxation time has been made from the transition temperature to the melting point. It was impossible to measure the spin-spin relaxation time for the cubic phase

Assuming that paramagnetic relaxation is irrelevant in the sample, the strong relaxation which is • stronger than that caused by dipolar interaction, and which was observed in the cubic phase is attributed to the quadr •upolar relaxation by translational diffusion due to the extra vacancies octahedral positions and also due to the rotation of the sulphate ions in the lithium sulphate solid. The measurement of the relaxation time in the lithium sulphate doped with lithium tungestate confirms this idea.

Studies have also been made of the lithium sulphate-zinc sulphate system using NMR technique.