Dielectric Behavior and the Devil's Staircase in the SmCα * Phase of an Antiferroelectric Liquid Crystal, 4-(1-methylheptyloxycarbonyl)phenyl 4′-octylcarbonyloxybiphenyl-4-carboxylate

We have observed an increase of the dielectric constant under a bias electric field in the SmC A * and SmC α * phases in 4-(1-methylheptyloxycarbonyl) phenyl 4 ′ -octylcarbonyloxybiphenyl-4-carboxylate. This implies a field-induced phase transition to the ferrielectric and/or to the ferroelectric phases. The transitions were also clearly observed in the field-induced apparent tilt angles in these phases. The electric-field-induced Devil's staircase was confirmed in the SmC α * phase. Using these observations, a T (temperature)- E (electric field) phase diagram was drawn.