Study of crystalline growth, structural characteristics, optical behavior, thermo and dielectric properties of isoniazid single crystal

In this study, isoniazid single crystals were synthesized using solvent mediated followed by slow solvent evaporation
techniques for testing the electro-optics application. Powder XRD analysis was used to record several scattering peaksfor the obtained grown material, and the presence of scattering peak positions results correlated to the reportedscattering peak position of the above title compound’s orthorhombic crystal structure. Further, the single crystal XRDanalysis confirmed the orthorhombic crystal system based on the obtained lattice parameters of synthesized crystal.The grown crystal was scanned using an FT-IR analysis, and its chemically attached functional groups were detected inthe spectrum. According to UV–visible studies, isoniazid has a transmittance value of more than 90 %. In addition, thetransmittance behavior of the grown compound changed significantly depending on its wavelength. The nonlinear optical property study of the grown crystal was characterized, and the results of the second harmonic generationefficiency values correlate with those of standard reference crystal. Thermal stability and melting temperature of thegrown crystal were investigated using TG/DTA studies. The temperature vs weight loss plot revealed weight loss in thetemperature range of 225 °C to 400 °C for the grown crystal. Using differential thermo gravimetric analysis (DTA), themelting temperature of the synthesized crystal was determined to be 170 °C. The dielectric constant and dielectric lossresponses of grown isoniazid crystals are found to be less at high frequencies and increase exponentially at lowfrequencies due to the presence of polarization effects
.