Structurally related dicalcium silicate phases

From careful measurement and indexing of the powder diffraction patterns obtained for pure dicalcium silicate, unit-cell parameter vs temperature plots have been obtained covering the β and α' dicalcium silicate phases. It is found that these phases are all closely related, the temperature variations, for example, being gradual from 293 K (the β phase) and more discontinuous between 993 and 1043 K corresponding to the β = α'_L transition. Our conclusions lead to a simplified dicalcium silicate transformation scheme which requires that there is no phase differentiation within the β-phase regime.