THE A-C-A PHASE DIAGRAM OF MIXED LIQUID CRYSTALS: A PHOTON TRANSMISSION STUDY

Ultraviolet/visible photon transmission technique was applied to study the phase diagram of the BOPDOB-BOPOOB liquid crystal system. It was observed that the nematic-smectic A transition becomes first order, as the weight percentage of BOPDOB in the binary mixture is increased. The smectic A-C-A reentrance disappears when the BOPDOB percentage approaches 100 (pure BOPDOB). We also present the smectic A-C transition temperatures and the critical exponents β of the all samples. The values of the exponent are consistent with mean-field theory.