Probing the impact of bent-core mesogen on the dielectric relaxations of ferroelectric liquid crystal

•Modulation in dielectric relaxations of ferroelectric liquid crystal (SCE9) by the dopant bent-core mesogen derived from the oxadiazole bisaniline moiety.•Dielectric studies confirm modulation in Goldstone mode, p-UHM and soft mode of ferroelectric liquid crystal by dopant bent-core mesogen.•SmC*-SmA* phase transition of ferroelectric liquid crystal is highly dependent on concentration of dopant bent-core mesogen. The modulation in dielectric relaxations of a conventional ferroelectric liquid crystal (FLC, SCE9) material by doping the bent-core mesogen (BCM) derived from the oxadiazole bisaniline moiety has been greatly investigated using frequency-temperature dependent dielectric spectroscopy. The application of probing ac voltage (i.e., oscillating voltage, 800 mV) has clearly shown the presence of partially unwound helical mode (p-UHM) along with Goldstone mode (GM). However, the temperature-dependent dielectric studies further demonstrate that p-UHM gets merged with GM at higher temperatures and hence becomes difficult to observe it separately. It appears that doping of BCM into FLC leads to the suppression of p-UHM at lower temperature, but with the increase in the concentration of dopant beyond a certain point, p-UHM mode reappears. Moreover, the significant decrement (∼9 °C) in SmC*-SmA* phase transition temperature of FLC with increase in the dopant BCM concentration up to 3 wt%. We believe that such studies would be certainly useful for the understanding of the plausible interaction between two different shaped mesogens (i.e., rod and bent-core) present in the mixture and could pave the way forward to the use of one type of mesogen in the modulation of the dielectric properties of other mesogen.