Nature of Dielectric Response of Phenyl Alcohols

Phenyl alcohols (PhAs) are an interesting class of materials, for which the dielectric response reveals only the presence of single prominent Debye-like (D) relaxation, interpreted as a genuine structural (α) process. Herein, we have performed dielectric and mechanical measurements on a series of PhAs characterized by the varying length of the alkyl chain and found that this interpretation is not valid. Analysis of the derivative of the real part of the complex permittivity together with the mechanical and light scattering data clearly indicated that the prominent dielectric D-like peak is actually a superposition of both cross-correlation between dipole-dipole (D-mode) and self-dipole correlation (α-process) and that the distinguished α-mode exhibits a similar ("generic") shape of PhAs independently to their molecular weight and applied experimental technique. Therefore, the data presented herein contribute to the whole discussion focused on the dielectric response function and universality (or diversity) of the spectral shape of the α-mode of polar liquids.