Further Consideration of Phases in the System Ba ₂ SiO ₄ –Ca ₂ SiO ₄

Abstract

The results of an investigation of the system Ba 2 SiO 4 –Ca 2 SiO 4 by powder X‐ray and electron diffraction suggest a greater complexity than supposed hitherto. The previously recognized phases α, α′ h α′ l , X, T, and the newly reported Y have room‐temperature structures that are modulated distortions of hexagonal (or pseudohexagonal) parent structures. Each displays characteristic and distinctive modulations. The phases are more readily distinguished in this way than by their unit‐cell dimensions and compositions which, for a given phase, can vary with bulk starting composition and thermal history.