Peculiarities of light transmission at nematic - Isotropic liquid and isotropic liquid - Nematic phase transitions

Abstract

The optical transmission in thermotropic nematogens for a large temperature interval and in regions of direct and reverse phase transitions between the nematic mesophase and isotropic liquid has been investigated. The character of the optical transmission has been compared with that of the texture transformations of the nematogens. The thermal hysteresis effect for the optical transmission vs. temperature has been found. The shift of the isotropic liquid - nematic phase transition temperature and widening of the biphasic region of this phase transition have been observed.