In the present paper a novel method is presented, allowing us to measure the saddle-splay elastic constant K24 and consequently the mixed splay-bend elasticity K12, in the frame of the continuum-theory. On a weakly anchored nematic cell with a pure bend distortion a twist deformation is superimposed, due to a magnetic field greater than Freedericksz’ threshold. The free energy term of the K13-type is rigorously zero, whereas the term affected by K24 is different from zero, and is dependent only on the twist angles at the walls, and not on their first derivatives. Such a situation allows us to solve the variational problem and to evaluate K24, by measuring the shift of the critical field, provided the anchoring strengths at both walls are suitably chosen.
|Titolo:||On the surface-type elastic constant K24 in nematics|
|Data di pubblicazione:||1987|
|Digital Object Identifier (DOI):||10.1080/00268948708070971|
|Appare nelle tipologie:||1.1 Articolo in rivista|
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