Linked Life Data

20365387

Source:http://linkedlifedata.com/resource/pubmed/id/20365387

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Pt 1
pubmed:dateCreated
2010-4-6
pubmed:abstractText
We have studied mesogenic properties in the smectic- A(d)P(A) phase of an asymmetric bent-core liquid crystal by means of polarizing optical microscopy, second-harmonic generation (SHG), electro-optical (EO), and dielectric measurements. In homeotropically aligned cells, EO switching is clearly observed from a schlieren texture with both four- and two-brush defects to a uniform bright domain under the application of very low in-plane electric field below 1 V/microm. The phase is SHG active under an electric field, i.e., SHG gradually increases without a threshold and saturates with the increasing field. In homogeneous cells, by applying triangular wave field at saturated voltage, the splitting of the polarization switching current peak is observed, indicating that the mesophase is antiferroelectric. The dielectric studies indicate a Debye-type relaxation of the transverse dipoles associated with the rotation of the molecules about their long axis. The dc bias-dependent dielectric relaxation time and the dielectric strength suggest that a field-induced antiferroelectric-ferroelectric phase transition occurs continuously beyond 1.2 V/microm and is reversible. The field-dependent texture observation is consistent with the dielectric measurements. Two possible models are proposed to interpret the continuous phase transition.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jan
pubmed:issn
1550-2376
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
81
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
011703
pubmed:year
2010
pubmed:articleTitle
Polar switching in the smectic- A(d)P(A) phase composed of asymmetric bent-core molecules.
pubmed:affiliation
Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't