Smectic membranes in motion: Dynamic studies with x-ray photon correlation spectroscopy and neutron spin echo

Prof.dr. Wim H. de Jeu, FOM-Institute AMOLF, Amsterdam, The Netherlands

I will report measurements of low-dimensional fluctuations in smectic liquid crystal membranes in the range of 10 ns to 10 ms using both x-ray photon correlation spectroscopy (XPCS) neutron spin echo (NSE). XPCS probes surface tension-dominated relaxation times. In this regime fluctuations with long wavelengths reveal an oscillatory damping, while fluctuations with a shorter wavelength show a simple exponential decay. NSE reveals a new regime, determined by bulk elasticity, in which the fast relaxation times decrease with the wave vector.  

W.H. de Jeu, B.I. Ostrovskii, and A.N. Shalaginov, Rev. Mod. Phys. 75, 181 (2003)