Phase Transitions in LiAl 5 O 8

LiAl 5 O 8 exists in many forms. The equilibrium high‐temperature form (I) has a spinel structure. It undergoes a first‐order reconstructive transformation at 1295°× 5°C to an equilibrium low‐temperature form (II) with primitive cubic symmetry, the unit edge changing from a 0 = 7.921 A (I) to a 0 = 7.907 A (II). In addition, a whole series of phases (II‐metastable) exist with the same symmetry as II but with a disorder different from I → II disorder.