Avtor/Urednik		Muševič, I; Rastegar, A; Čepič, Mojca; Žekš, B; Čopič, Martin
Naslov		Observation of an opticlike phase mode in an antiferroelectric liquid crystal
Tip		članek
Vir		Phys Rev Lett
Vol. in št.		Letnik 77, št. 9
Leto izdaje		1996
Obseg		str. 1769-72
Jezik		eng
Abstrakt		We have observed an acousticlike and an opticlike branch of phase excitations in a quasielastic light-scattering experiment performed in the antiferroelectric smectic-C*A phase of 4-(1-ethylheptyloxycarbonyl)phenyl-4'-alkylcarbonyloxy biphenyl-4-carboxylate. In contrst to the nearly gapless acoustic plason branch, the opticlike phase excitations always have a finite relaxation rate. The phenomenon is a direct consequence of a doubling of a smectic unit cell at the transition from the smectic-A phase and is in remarkable agreement with a Landau-type model.
Deskriptorji		BIOPHYSICS CRYSTALLIZATION MODELS, THEORETICAL