Electric field effect on the SmA - SmC phase transition

Abstract

Electric field effect on the SmA - SmC* phase transition has been studied with the electrooptical methods. A very sharp peak of the light modulation depth has been observed in the absence of dc electric field. This peak is related to the maximum intensity of the soft mode and can be used as an excellent indicator of the SmA — SmC* phase transition. When a dc electric field is applied, this peak shifts to higher temperatures and its amplitude decreases considerably. The observed distinct broadening of the peak indicates that in the presence of electric field the SmA — SmC* phase transition is blurred. The critical temperature obtained from the Curie-Weiss law is independent of the electric field strength as opposed to the Curie constant which displays a distinct dependence on field in the SmC* phase.