Pseudobinary Phase Relations of Li 2 Ti 3 O 7

The Li 2 O‐TiO 2 pseudobinary phase diagram was determined from 50 to 100 mol% TiO 2 by DTA, microscopy, and X‐ray analysis; Li 2 Ti 3 O 7 effectively melts congruently at 1300° and decomposes eutectoidally at 940°C. A solid solution based on Li 2 TlO 3 from 50 to ∼65 mol% TiO 3 was observed to exist at >930°C. A new metastable phase was discovered with a composition of ∼75 mol% TiO 2 and with a hexagonal unit cell (8.78 by 69.86 × 10 −1 nm). Discrepancies in the literature regarding some of these phase equilibria are reconciled.