Thermal expansion coefficients of zirconolite (CaZrTi2O7) and perovskite (CaTiO3) from x-ray powder diffraction analysis

Abstract

The thermal expansion coefficients of zirconolite, both ordered and disordered, and perovskite, were measured by X-ray powder diffraction analysis in the temperature range 25–1200°C. The principal results are: (1) The mean thermal expansion coefficients (K−1) of ordered zirconolite are:αa = (11.35±0.25) × 10−6;αb = (8.72± 0.22) × 10−6;αc = (10.0 ±0.5) × 10−6. (2) The mean thermal expansion coefficients (K−1) of disordered zirconolite areα∥ = (9.89±0.15) × 10−6 in the (001) plane and α⊥ = (9.37±0.14) × 10−6 normal to (001). (3) The mean thermal expansion coefficients (K−1) of perovskite are:αa = (7.86±0.30) × 10−6;αb = (13.46±0.17) × 10−6;α c = (16.55±0.26) × 10−6. © 1992 Published by Elsevier B.V.