Chiroclinic effect and the phase diagram of achiral polar molecules in the antiferroelectric smectic B_2 phase

摘要

The paper presents a detailed analysis of the effects of chiral doping on antiferroelectric B2 subphases in bent core systems. The studied system exhibits the phase sequence SmA ? SmAP_A ? SmC_SP_A. The chiral dopant induces the tilt in the SmAP_A phase or the tilt modulation in the SmC_SP_A phase, which is known as the chiroclinic effect, but it also influences the stability ranges and the order of the transition between the phases. The order of the phase transition changes from a continuous for weak effects of chiral doping to discontinuous for strong effects. Competition of interactions results in changes of the phase sequences, which are resumed in the phase diagram. The method that leads to these findings, which could be used for the analysis of other similar systems, is briefly presented as well.