Nonlinear Dielectric Study of Critical Behavior Near Isotropic-Nematic Phase Transition

Abstract

We studied Isotropic-Nematic (I-N) phase transition by nonlinear dielectric measurement. The third-order nonlinear permittivity ϵ₃ was obtained from the third harmonic component of the electric displacement under AC electric field. The obtained ϵ₃ shows the critical behavior in I phase near I-N transition point with the critical component of one. This result agrees well with the critical behavior predicted by mean − field theory, but that of the relaxation time deviates from the theoretical prediction.

Keywords:

• critical behavior
• dielectric relaxation
• I-N phase transition
• mean-field theory
• nonlinear permittivity