Title
Pressure-induced structural transformations in lanthanide titanates: La2TiO5 and Nd2TiO5
Document Type
Article
Publication Date
11-1-2010
Abstract
The structure of orthorhombic rare earth titanates of La 2TiO5 and Nd2TiO5, where Ti cations are in five-fold coordination with oxygen, has been studied at high pressures by X-ray diffraction (XRD), Raman scattering measurements, and quantum mechanical calculations. Both XRD and Raman results indicated two pressure-induced phase transitions during the process. An orthorhombic super cell (a×b×2c) formed at a pressure between 6 and 10 GPa, and then transformed to a hexagonal high-pressure phase accompanied by partial decomposition. The hexagonal high-pressure phase is quenchable. Detailed structural analysis indicated that the five-coordinated TiO5 polyhedra remain during the formation of super cell, but the orthorhombic-to-hexagonal phase transition at high pressures is a reconstructive process, and the five-fold TiO coordination increased to more than 6. This phase transition sequence was verified by quantum mechanical calculations. © 2010 Elsevier Inc. All rights reserved.
Publication Source (Journal or Book title)
Journal of Solid State Chemistry
First Page
2636
Last Page
2643
Recommended Citation
Zhang, F., Wang, J., Lang, M., Zhang, J., & Ewing, R. (2010). Pressure-induced structural transformations in lanthanide titanates: La2TiO5 and Nd2TiO5. Journal of Solid State Chemistry, 183 (11), 2636-2643. https://doi.org/10.1016/j.jssc.2010.09.014