Dynamic properties near the nematic-smectic-A transition by ultrasonic absorption

Ultrasonic shear and 'capillary viscosity study of 4-cyano-4'-n-heptylbiphenyl in the nematic and the isotropic state

“…Our data on the ultrasonic shear of the present compound, 4-cyano-4'-n-heptylbiphenyl or 7-CB, are new and our data on capillary viscosity are in good agreement with data obtained by other workers before [8]. Ultrasonic shear on the related compound 5-CB has been studied by Kiry et al [6,7], whereas low frequency oscillatory shear studies have been carried out by Clark et al [1], and by Skarp et aL [2].…”

“…The data for 7-CB are shown in figure 3. For the nematic state the following relationships between the observed viscosities and the Leslie coefficients can be written down [4,6].…”

Relative behaviour of sound absorption and dispersion near the nematic-smectic-A phase transition in TBBA and CBOOA : comment and new results

“…The study that Kiry and I made of the A-N transition in CBOOA [6][7][8] revealed that this transition is characterized by weak pretransitional effects. Our analysis above TAN [8] showed that the ultrasonic absorption has two components.…”

“…At the smectic-A-nematic (A-N) phase transition, however, ultrasonic measurements are rather scarce [3][4][5][6][7][8][9] and the current situation appears confusing. This letter is an attempt to clarify this situation.…”