θImpedance spectroscopic investigation of chiral additive induced wide range blue phases

Impedance spectroscopic investigation has been performed for a chiral additive (10%wt) doped biphenyl derivative possessing two successive wide ranges blue phases (BP) viz. cubic BP and BPIII. Experimental attention is focused in BPIII along with two BPIII related phase transitions, i.e., cubic BP-BPIII and BPIII-Isotropic phase (I). Dielectric pre-transitional effect has been observed in the vicinity of I-BPIII transition exhibiting convex-shaped anomaly (CSA). Anomalous DC bias field dependences are observed in frequency-dependent real part and imaginary part of complex dielectric permittivity profile in pre-transitional BPIII, BPIII and cubic BP phases considered being signatures of respective phases. Temperature and DC bias field dependent relaxation frequency indicates bias field induced enhancement of domain size in BPIII. Also a noticeable change of activation energy is observed from its estimated values in BPIII and pre-transitional BPIII region by Arrhenius equations.