Co-ordination of Yb 3+ in phosphate, silicate, and germanate glasses

Abstract

Radiation causes considerable internal decomposition of lithium hydride, ultimately resulting in gross swelling and formation of bubbles of hydrogen and particles of metallic lithium. When irradiated LiH is heated, stored energy is evolved as the free lithium and hydrogen back-react to form LiH. A mechanism is proposed that describes the back-reaction as proceeding by H2 molecules ‘redissolving’ in the lattice, and then migrating to Li particles, where recombination occurs. An expression is developed that relates the size and the concentration of the hydrogen bubbles to the temperature characterizing the release of the stored energy. The data are shown to be consistent with this model.