Phase evolution, dielectric and impedance spectroscopic study of SrNb₂O₆ columbite phase

Abstract

Strontium niobate SrNb₂O₆ has been synthesized by columbite solid-state reaction method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and temperature as well as frequency dependence of dielectric and impedance study. XRD analysis indicates single phase formation of the compound with ~180 nm crystallite size. Study of SEM micrographs pointed out that prepared material has good sinterability and enough density with homogeneous grain distribution. It was found that the magnitude of relative dielectric constant (ε_r) was relatively high with low dielectric loss compared with reported columbite compounds. Impedance spectroscopy was used to characterize the electrical behavior of the compound. AC impedance spectrum results indicate that the relaxation mechanism of the material is temperature dependent and has bulk and grain boundary contribution in different temperature ranges.