Electroclinic effect in the N* phase near A N* S_AS*_Cmulticritical point

Abstract

Abstract From structural, thermodynamical analysis and polarization measurements, we show that the N* S*C phase transition of the homologous n = 8 of a biphenyl benzoate series appears near a N* SA S*C multicritical point. Dielectric measurements detect a relaxation process in the N* phase. The temperature dependence of the dielectric strength and of the critical frequency are similar to these of the soft mode classically observed in the SA phase. This relaxation process is attributed to an electroclinic effect in the N* phase near a N* S*C phase transition. Its large amplitude is probably connected with the proximity of the N* SA S*C multicritical point.