A Thermogravimetric and NMR Study of β-Aluminas

Abstract The Na+ tracer diffusion coefficient and the 27Al NMR spin lattice relaxation time in Na β-alumina display an anomalous temperature dependence near 470 K. These phenomena are related to absorption of water which takes place when the temperature is decreased below 470 K. Water absorption processes in pure and partially substituted β-aluminas are studied by thermogravimetric analysis. Their effects upon conductivity are qualitatively discussed.