Pressure-driven reentrant phenomena in liquid crystals: the role of inverse layer spacing
The occurrence of pressure-driven reentrant phenomena observed in high-pressure experimental studies in some achiral mesogenic materials has been explained using a thermodynamic model based on Landau-de Gennes theory. In this approach, the free-energy is expanded in terms of nematic,
smectic A order parameters and the couplings (cubic and biquadratic) between them. The basic theme here is that the 'inverse layer spacing', which mimics an order parameter, becomes coupled to the nematic and smectic A order parameters. Secondly, in addition to the order parameter couplings
the N-SA metastable temperature (which appears due to elimination of inverse layer spacing from the free-energy density expression) becomes pressure dependent. The occurrence of a pressure-driven reentrant nematic phase is explained in terms of these three pressure-dependent parameters. They
all show smooth but rapid variation at the critical pressure beyond which nematic reentrance appears.
Keywords: Landau-de Gennes theory; liquid crystals; phase transitions; reentrant phenomena
Document Type: Research Article
Affiliations: Department of Physics, Banaras Hindu University, Varanasi, India
Publication date: 01 February 2010
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Ingenta Connect is not responsible for the content or availability of external websites
- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content