Yoav Tsori

We study the shift in the critical temperature T_c in binary mixtures in strong electric fields. In experiments we measure the nonlinear dielectric effect (NDE) in a mixture of nitrobenze and n-octane and calculate Piekaras factor. We find that the critical anomaly of Piekaras factor is a function of an electric field strength. We propose to explain this observation as a result of a downward shift of T_c, and this allows us to calculate (εT_c/εE²) = (-22 ± 10) × 10^-16 (K m²)/V². In the theoretical part we amend Landau and Lifshitzs formula and show that the downward shift of T _c can be estimated from a simple mean-field theory taking into account the linear and quadratic terms in an expansion of the constitutive relation μ(x) between the electric constant μ and mixture composition x.