The static distortions in a homogeneously aligned nematic liquid-crystal film in crossed electric and magnetic fields are theoretically analyzed. Both fields are orthogonal to the undistorted molecular alignment and destabilizing. In the limit of small distortions, a first-order transition between two distorted configurations, with bistability and hysteresis, is obtained if the dielectric anisotropy parameter 1-ε∥/ε⊥ is lower than the elastic anisotropy parameter (k3-k2)2/(4k1k2), where k1, k2, and k3 are the Frank elastic constants. This condition is satisfied by many commonly used nematic materials. At higher distortions an inversion point is found, above which the transition becomes of the second order. At this point a phenomenon similar to the critical opalescence of fluids is expected.
Bistability induced by crossed electric and magnetic fields in a nematic film / Barbero, Giovanni; Miraldi, Elio; Oldano, C.. - In: PHYSICAL REVIEW A, GENERAL PHYSICS. - ISSN 0556-2791. - 38:6(1988), pp. 3027-3034. [10.1103/PhysRevA.38.3027]
Bistability induced by crossed electric and magnetic fields in a nematic film
BARBERO, GIOVANNI;MIRALDI, ELIO;
1988
Abstract
The static distortions in a homogeneously aligned nematic liquid-crystal film in crossed electric and magnetic fields are theoretically analyzed. Both fields are orthogonal to the undistorted molecular alignment and destabilizing. In the limit of small distortions, a first-order transition between two distorted configurations, with bistability and hysteresis, is obtained if the dielectric anisotropy parameter 1-ε∥/ε⊥ is lower than the elastic anisotropy parameter (k3-k2)2/(4k1k2), where k1, k2, and k3 are the Frank elastic constants. This condition is satisfied by many commonly used nematic materials. At higher distortions an inversion point is found, above which the transition becomes of the second order. At this point a phenomenon similar to the critical opalescence of fluids is expected.File | Dimensione | Formato | |
---|---|---|---|
1402938.pdf
non disponibili
Tipologia:
2. Post-print / Author's Accepted Manuscript
Licenza:
Non Pubblico - Accesso privato/ristretto
Dimensione
311.74 kB
Formato
Adobe PDF
|
311.74 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11583/1402938
Attenzione
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo