Analysis of the ferroelectric phase transition in (formula presented) by group theoretical methods and first-principles calculations
Group theoretical methods are applied to a ferroelectric phase transition in barium aluminate (formula presented) The atomic displacements from x-ray-diffraction data are decomposed into four modes: a primary order parameter and three secondary order parameters. The spontaneous polarization (formula presented) is shown to arise from a secondary order parameter, resulting in a very small value of (formula presented) as is typical of other improper ferroelectrics. Using a first-principles computational method, we show that the primary order parameter becomes unstable, and is driven to a nonzero value at the phase transition. Through coupling, the nonzero primary order parameter then drives the secondary order parameters to nonzero values as well. © 2002 The American Physical Society.
Duke Scholars
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Fluids & Plasmas
- 09 Engineering
- 03 Chemical Sciences
- 02 Physical Sciences
Citation
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Fluids & Plasmas
- 09 Engineering
- 03 Chemical Sciences
- 02 Physical Sciences