Static periodic distortion above bend Freedericksz transition in nematics

Kini, U.D.

Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/2917

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DC Field	Value	Language
dc.contributor.author	Kini, U.D.	-
dc.date.accessioned	2007-06-18T04:40:40Z	-
dc.date.available	2007-06-18T04:40:40Z	-
dc.date.issued	1990-02	-
dc.identifier.citation	Liquid Crystals, 1990, Vol.7, p185 - 201	en
dc.identifier.issn	0267-8292	-
dc.identifier.issn	1366-5855 (online)	-
dc.identifier.uri	http://hdl.handle.net/2289/2917	-
dc.description	Restricted Access.	en
dc.description.abstract	The linearized mathematical model developed by Allender, Hornreich and Johnson [1987, Phys. Rev. Lett., 59, 2654], for explaining the appearance of the magnetic field induced stripe phase (SP) above the bend Freedericksz threshold in a nematic close to the smectic transition, is generalized to the case of uniform tilt b.thetas1 of the nematic director n0 away from the homeotropic with the field H acting normal to n0. Calculations of SP threshold and domain wave vector Q are presented for different elastic ratios and tilts b.thetas1, by exact computation of the ground state homogeneous deformation (HD) under the rigid anchoring hypothesis. Approximate estimates based on energetics, explicitly taking into account the modal symmetry of perturbations, agree well with the results of exact calculations based on the solution of torque equations. For homeotropic alignment (b.thetas1 = 0) calculations predict that the SP domain width should decrease when the sample is heated away from the smectic transition point; at a given temperature when H is rotated through a small angle with respect to the sample planes the domains should grow wider. These points can be verified experimentally. It is also shown that for sufficiently high initial tilt b.thetas1 away from the homeotropic director alignment, SP may be quenched. Materials, such as nematic polymers, which exhibit static periodic domains (PD) in splay geometry (of the kind discovered by Lonberg and Meyer, 1985, Phys. Rev. Lett., 55, 718) may also show SP for director tilts b.thetas1 close to the homeotropic. It appears possible to make tentative predictions regarding the effects of weak anchoring and oblique magnetic fields on the SP threshold and domain wave vector.	en
dc.format.extent	836853 bytes	-
dc.format.mimetype	application/pdf	-
dc.language.iso	en	en
dc.publisher	Taylor & Francis	en
dc.relation.uri	http://dx.doi.org/10.1080/02678299008029207	en
dc.rights	1990 Taylor & Francis	en
dc.title	Static periodic distortion above bend Freedericksz transition in nematics	en
dc.type	Article	en
Appears in Collections:	Research Papers (SCM)

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