Incoherent Quasielastic Neutron Scattering Study of Molecular dynamics of 4-n-cyano-4'-octylbiphenyl

TL;DR

This study uses incoherent quasielastic neutron scattering to analyze molecular dynamics in a liquid crystal, identifying translational diffusion and rotational motions across different time scales.

Contribution

It provides a detailed analysis of molecular motions in 4-n-cyano-4'-octylbiphenyl using neutron scattering, highlighting relaxation processes over a wide time range.

Findings

Translational diffusion occurs on nanosecond timescales.

Uniaxial molecular rotations occur on picosecond timescales.

Results are compared with existing literature data.

Abstract

We report incoherent quasielastic neutron scattering experiments on the thermotropic liquid crystal 4-n-cyano-4'-octylbiphenyl. The combination of time-of-flight and backscattering data allows analyzing the intermediate scattering function over about three decades of relaxation times. Translational diffusion and uniaxial molecular rotations are clearly identified as the major relaxation processes in respectively the nanosecond and picosecond time scales. The comparison with literature data obtained by other techniques is discussed.