Thermal expansion coefficients of zirconolite (CaZrTi 2O 7) and perovskite (CaTiO 3) from X-ray powder diffraction analysis

Abstract

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:α a = (11.35±0.25) × 10 −6;α b = (8.72± 0.22) × 10 −6;α c = (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:α a = (7.86±0.30) × 10 −6;α b = (13.46±0.17) × 10 −6;α c = (16.55±0.26) × 10 −6.