Title:	Experimental determination of the elastic constant k13 of a nematic liquid crystal
Authors:	Madhusudana, N.V. Pratibha, R.
Issue Date:	Feb-1990
Publisher:	Gordon and Breach Science Publishers.
Citation:	Molecular Crystals and Liquid Crystals, 1990, Vol.179 , p207-216
Abstract:	The elastic constant k13 is the coefficient of a divergence term in the free energy density and involves the second derivative of the director field. Thus its influence is felt only at the surface of the sample. We have analysed the optical path difference of a hybrid aligned nematic liquid crystal PCH7 taken in a cell which has a weak homeotropic alignment on one glass plate and a strong homogeneous alignment on the other. We use the approximation that solutions in the class of Euler-lagrange equations are valid up to the boundaries and extract both k13 and the anchoring energy at the homeotropically aligned surface. In view of the recent argument by Oldano and Barbero that the k13 term by itself may lead to discontinuities in the director configuration near the surfaces our measurements may be taken to yield an 'effective' value which may have contributions from other terms influencing the director configuration at the surface.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/2340
ISSN:	1058-725X
Alternative Location:	http://dx.doi.org/10.1080/00268949008055371
Copyright:	1990 OPA (Overseas Publishers Association) N.V.
Appears in Collections:	Research Papers (SCM)

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