Dielectric relaxation by restricted rotational diffusion

✍ Scribed by Mark P. Warchol; Worth E. Vaughan

• Publisher: Elsevier Science
• Year: 1978
• Weight: 590 KB
• Volume: 13
• Category: Article
• ISSN: 0378-4487
• DOI: 10.1016/0378-4487(78)80053-3

✦ Synopsis

The dynamics of rotational diffusion in a cone is characterized by solving the rotational diffusion equation subject to the boundary condition that the system not contain sources or sinks of probabilitydensity. The result is used to construct the dipolar autocorrelation function. To a good degree of approximation the dipolar autocorrelation function consists of a constant (unrelaxable) portion which may be calculated from the cone angle plus a portion which decays exponentially. The calculation relates to the dielectric behavior of rigid molecules trapped in matrices and provides a prediction for the shape of the as yet unobserved dielectric absorption at high frequencies for such systems. The relation of the model to the geometrical properties of actual molecules in real cavities is discussed. Dielectric data for rigid molecules in supercooled decalinare interpreted in terms of the model.