Emergence of long-range order in BaTiO3 from local symmetry-breaking distortions.

Journal article

By using a symmetry motivated basis to evaluate local distortions against pair distribution function data (PDF), we show without prior bias, that the off-centre Ti displacements in the archetypal ferroelectric BaTiO3 are zone centred and rhombohedral-like across its known ferroelectric and paraelectric phases. We construct a simple Monte Carlo (MC) model which captures our main experimental findings and demonstrate how the rich crystallographic phase diagram of BaTiO3 emerges from correlations of local symmetry-breaking distortions alone. Our results strongly support the order-disorder picture for these phase transitions, but can also be reconciled with the soft-mode theory of BaTiO3 that is supported by some spectroscopic techniques.

Authors: Senn, M; Keen, D; Lucas, T; Hriljac, J; Goodwin, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review Letters
• Volume: 116
• Issue: 20
• Pages: 207602
• Publication date: 2016-05-01
• DOI: 10.1103/PhysRevLett.116.207602
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English