Bias-tuned dielectric properties and Non-Debye relaxation in vanadium doped BaSnO3 nanocubes

Abstract

Pure and vanadium doped BaSnO3 samples were fabricated by using simple solid-state reaction method. Detail characterizations of the samples via x-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive analysis of x-rays and x-ray photoelectron spectroscopy confirmed the proper phase formation, morphology, composition and desired doping of the samples. V doping was identified as a crucial factor which can determine the dielectric properties of BaSnO3 in a wide range of frequency. Here we report for the first time, detail investigation on the dielectric properties of V doped BaSnO3 under different bias voltages. It was observed that dielectric constant and conductivity both were decreased significantly after higher doping (x = 0.03) and with DC bias, dielectric constants of all the samples were increased in low frequency range (<10 KHz). These results were accounted for the change in grain and grain boundary resistances with doping as well as with applied DC bias. Parallel effect of defect states and polarization occurring due to vanadium doping were also identified as key factors controlling the dielectric properties. Non-Debye type relaxation of charge carriers was confirmed in pure and doped BaSnO3 samples using Cole-Davidson formalism. Moreover, this method of dielectric property variation may be extended for other perovskite systems also.