Orientational dielectric relaxation of collisionless molecules

Abstract

The generation of the orientation component of the polarization of matter in an electric field has previously been thought to require interaction of molecules with their neighbors. It is demonstrated that, even in the absence of collisions between neighboring molecules, hot isolated polyatomic molecules can reorient in response to an external field, thereby giving rise to the orientation component of polarization. This reorientation occurs through the interaction of rotation with molecular vibrations, which provides a heat bath to establish thermal rotational equilibrium. This effect is demonstrated for o-difluorobenzene, o-dichlorobenzene, and p-chlorotoluene, with an inhomogeneous electric field used to deflect molecular beams of these molecules.