Effect of nitrogen radio frequency plasma on the structure, dielectric anisotropy, and electrical performance of liquid crystal nanocomposite

This study investigates the influence of nitrogen radio-frequency plasma treatment on the permittivity and impedance characteristics of a liquid crystal-manganese (III) oxide nanoparticle composite over a wide frequency and temperature range. The results show that both the parallel and perpendicular components of permittivity decrease with increasing frequency and reach a stable value at higher frequencies, reflecting polarization saturation due to interfacial dipole. The maximum dielectric anisotropy was observed in the sample containing nanoparticles treated for 2 min, attributed to improved nanoparticle dispersion and stronger molecular coupling within the liquid crystal matrix. Plasma exposure was also found to reduce impedance while enhancing anisotropy, highlighting its role in optimizing the electro-optical response of the system. Equivalent circuit analysis of impedance spectra revealed reduced resistance and modified interfacial capacitance, consistent with morphological changes confirmed by structural characterization. Overall, nitrogen plasma treatment provides a controllable and efficient approach to tune surface properties, dielectric performance, and charge transport in LC-nanoparticle hybrid materials, showing promise for advanced electronic and display applications.