Effect of Gadolinium on the structural and dielectric properties of BCZT ceramics

The influence of Gadolinium (Gd) on Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramics prepared using high temperature (∼1300°C) solid-state reaction technique is investigated. The X-ray diffraction pattern of the sample confirms the formation of the single-phase compound in a tetragonal crystal structure at room temperature. Micro-structural analyses are recorded using scanning electron microscopy (SEM). Dielectric (i.e. εr. and tanδ) parameters of the compound as a function of temperature at selected frequencies are studied. Modified Curie–Weiss law is implemented to study the diffusivity of the material. For the investigation of the electrical conduction process, impedance spectroscopy and electrical modulus analysis have been utilized. The material shows negative temperature coefficient of resistance (NTCR)-type behavior, indicating its semiconducting characteristics. Studies of electric modulus signify the presence of hopping mechanism in the system. The ac conductivity spectra are found to obey Jonscher's universal power law.