Optical, Dielectric and Ferroelectric Characteristics of Gel Grown Erbium Tartrate Hexahydrate Crystals

Abstract

With an aim of finding a material suitable for microelectronic applications, experiments were performed to grow erbium tartrate crystals by gel encapsulation. The crystals grow with very well-developed and remarkably flat habit faces as revealed by micro-structural studies, using optical and scanning electron microscopy. The study reveals that the most prominent faces include {001}, {100} and {010}. The crystallographic data analysis of x-ray diffraction results, supplemented by trial-and-error software, shows that the compound crystallizes in a tetragonal crystal system with non-centrosymmetric space group. The high resolution x-ray diffraction results indicating the perfection of the grown crystals are presented. Results of ultraviolet–visible near infra-red (UV–Vis–NIR) spectra leading to determination of energy band gap of 5. 56 eV are described and discussed. The refractive index of the grown material comes out to be 1.40. Comparative analysis of dielectric characteristics of the grown material is made, both for the single crystal and powder form. The material is shown to be ferroelectric with low value of dielectric constant. Behaviour of dielectric constant, dielectric loss and alternating current (ac) conductivity on frequency of the applied ac field at different temperatures is described and discussed. The results are correlated with those of optical and high resolution x-ray diffraction. The material characteristics as revealed by the study suggest that the compound has the basic qualities of a promising material for microelectronic device applications.