Synthesis, characterization of Cr-Gd nanocomposites doped with yttrium possessing dielectric properties

Abstract

We report here, a set of perovskite oxide nanomaterials that has been prepared through co precipitation methods. Synthesis of nanocomposite material, chromium-gadolinium doped with various concentrations of yttrium was investigated for their dielectric properties. Nanocompositional hybrid materials were prepared by co precipitation method with composition of Cr0.3 Gd0.3 (Y2O3) x moles. In the present study yttrium is doped with x = 0.1-0.5 moles, the gelated precipitate of hybrid nanomaterials were calcinated at different temperatures and characterized by XRD, FT-IR, UV-Vis, SEM spectroscopic techniques. The doped Y2O3 to chromium and gadolinium multi component nanocomposite with different concentrations (0.1-0.5%). The dielectric constants of the pelletalized samples were examined at 300K and 320K temperature and materials showed variable dielectric polarization with respect to temperature and frequency. The precursor material used for the synthesis is chromium sulphate and gadolinium carbonate which are reduced in presence of triethanol amine (TEA).The aqueous mixture of greenish brown precipitate was filtered, washed with ethanol-water mixture (1:9 volume %) to remove any impurities present with the precipitate, dried at 50-100°C, heat treated at 650-750 °C and obtained pure nanocomposite. Findings: Spectroscopic studies showed that Y2O3 grain size was 12-60 nm in diameter and it’s over layer is 85% optically transparent. XRD pattern demonstrated the formation of hexagonal yttrium and dopant addition moderately affect the crystal structure. Higher dielectric constants were obtained with larger grain size of the nanocomposites.