Pressure Dependence of the Nematic State Temperature of a Compensated Cholesteric Liquid Crystal: Optical Rotatory Power Measurements with a Cholesteryl chloride and Cholesteryl nonanoate Mixture

At a certain temperature T n (nematic temperature) a mixture of two cholesteric components which separately form helices of opposite senses behaves like a nematic. An inversion of the helical structure occurs when passing T n , from a right-handed to a left-handed structure or vice versa. In the temperature-pressure space such compensated mixtures therefore will exhibit an inversion line which - on the basis of optical rotatory power measurements under high pressure - is presented for the first time.