Studies in Lithium Oxide Systems: V, Li ₂ O‐Li ₂ 0 B ₂ O ₃

Abstract

Nine compositions containing 40 to 68% B 2 O 3 were used to study the high‐lithia portion of the system Li 2 O‐B 2 O 3 by quenching and differential thermal analysis methods. The compounds 3Li 2 O 2B 2 O 3 and 3Li 2 O B 2 O 3 melted incongruently at 700°± 6°C, and 715°± 15°C., respectively. The compound 2Li 2 O B 2 O 3 is assumed to dissociate slightly below 650°± 15° C., although the data could also be interpreted as in‐congruent melting. Below 600°± 6°C. it does dissociate to the 3:2 and 3:1 compounds. In this narrow temperature interval the 2:1 compound had an inversion at 618°± 6°C. Both forms of the 2:1 compound could be quenched to room temperature. X‐ray diffraction data for the compounds are tabulated, and the complete phase diagram for the system Li 2 O‐B 2 O 3 is presented.