SYNTHESIS OF HIGH PURITY Li5ALO4 POWDER BY SOLID STATE REACTION UNDER THE H2 FIRING.

Ceramic breeders used in a fusion reactor blanket, which play a role in the production of tritium by the reaction with neutron, are required to have high lithium density in the pebble. Li₅AlO₄ contains lithium by high concentration and have a great ability of tritium breeder. However, in order to prepare the high purity powder of Li₅AlO₄, only a few methods with disadvantageous economically because of their requirement of a high-cost powder, Li₂O. In this study, Li₂CO₃ powder was used instead of Li₂O powder, which are not always commercially available, and a high-purity powder of α-Li₅AlO₄ and β-Li₅AlO₄ were synthesized via a solid state reaction. Mixed powders of Li₂CO₃ and Al₂O₃ with a molar ratio of 5:1 were fired at 630°C and/or 800°C in H₂ and/or O₂ for several hours. This low firing temperature inhibited the vaporization of lithium during the heating, so that the excess amount of lithium compounds was not necessary. A reaction process that α-LiAlO₂, γ-LiAlO₂, and Li₂O are produced as intermediate phases has been suggested. [ABSTRACT FROM AUTHOR]