Eur. Phys. J. E (2012) 35: 32
https://doi.org/10.1140/epje/i2012-12032-y

Regular Article

Biaxial surface order dynamics in calamitic nematics

¹ CNR-IPCF UOS di Cosenza, c/o University of Calabria, 87036, Rende, Italy
² Mechanics and Materials Department, University “Mediterranea” of Reggio Calabria, 89122, Reggio Calabria, Italy
³ Physics Department, University of Calabria, 87036, Rende, Italy
⁴ Département de Physique, Laboratoire de Physique de la Matière Molle, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia

^* e-mail: riccardo.barberi@fis.unical.it

Received: 19 January 2012
Revised: 19 March 2012
Accepted: 23 April 2012
Published online: 17 May 2012

Abstract

Thermotropic nematic materials relax strong distortions by lowering the nematic order: the uniaxial symmetry is broken and is locally replaced by biaxial domains. We investigated the dynamics of the nematic order near a boundary surface of an asymmetric π-cell submitted to an external electric field, close to the electric order reconstruction threshold. An unexpected phenomenon is observed close, but below the threshold: the biaxial order spreads on the surface inducing a consequent bulk topological behaviour equivalent to the splay-bend fast transition allowed by order reconstruction at higher voltage.