Determination of optical constants and polarizability studies on ferroic Tetramethylammonium Tetracholorozincate crystal

Abstract

Single crystal of Tetramethylammonium Tetrachlorozincate has been grown by slow evaporation method. The orthorhombic structure of the material is confirmed by single crystal XRD study. The formation of the material is further supported by Raman study predicting high orientation along ‘a’ axis of the crystal. Ferroelectric hysteresis loop gives the evidence for the ferroelectric behaviour of the material. In optical studies, the insulating behaviour of the material is established by Tauc plot obtaining a large value of indirect optical band gap energy which is agreeable with the band gap energy value calculated along ‘a’ axis. From the recorded reflectance values, the refractive index and dielectric constant values of the crystal have been calculated. The electronic polarizability also has been calculated using Clausius–Mossotti equation in the high frequency UV–vis–NIR optical region. In addition, the polarizability of the crystal in the lower frequency regions is determined via dielectric studies experimentally, and it is well matched with the theoretically obtained value from Penn analysis. Further, Penn analysis deduces the Plasmon and Fermi energy of the material.