7Li Nuclear Magnetic Resonance in (7Li,6Li) and (Li, Na) Triborate Glasses

Abstract
Spin‐lattice relaxation times for 7Li were measured as a function of temperature in two mixed‐isotope (7Li,6Li) triborate glasses and one mixed‐alkali (Li, Na) triborate glass. The rapid increase in relaxation rate above 400 K is believed to result from localized alkali motion. A mixed‐alkali effect was observed for such a motion, but it is shown not to be a mass effect.