Linear birefringence and X-Ray diffraction studies of the structural phase transition in titanite, CaTiSiO5

Bismayer, U.; Schmahl, Wolfgang W.; Schmidt, C. und Groat, L.A. (1992): Linear birefringence and X-Ray diffraction studies of the structural phase transition in titanite, CaTiSiO5. In: Physics and Chemistry of Minerals, Vol. 19, No. 4: pp. 260-266

Abstract

The antiferroelectric phase transition in titanite characterised by a collinear displacement of Ti-atoms from their central octahedral position is investigated using linear optical birefringence and X-ray diffraction techniques. Both methods indicate a continuous transition near 496 K and extra contributions to δΔn and X-ray intensity signals at higher temperatures. The critical exponent of the macroscopic order parameter is found to be β = 0.14 ± 0.02 and the transformation is interpreted in terms of a two-dimensional quasi-spin model. Topological features of the structure agree well with the spatial distribution of the diffuse scattering of the superstructure reflection 40 Mathematical expression.

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences > Crystallography and Materials Science
• Subjects: 500 Science > 550 Earth sciences and geology
• Language: English