Relaxation of the Langevin saturation in dilute solution of mesogenic 10-TPEB molecules

Measurements of the frequency dependence of the nonlinear dielectric increment for dilute solutions of 10-TPEB molecules (C10H21–∅–∅–CH2–CH2–∅–NCS) (where ∅=C6H4) in benzene have been performed at different temperatures. Two parallel electric fields, the quasi-static field of very high strength (107 V/m) and the alternating field (1 MHz–3 GHz) of low strength (102 V/m), are simultaneously applied to the system. In the nonlinear dielectric relaxation spectra two absorption bands, corresponding to molecular rotations around the long and short axes, have been observed. The results are interpreted in the framework of Coffeyʹs theory, extended to the case of two simultaneous relaxation processes.