Synthesis and anomalous behavior of electrical properties of Ba modified CaCu₃Ti₄O₁₂

Abstract

A perovskite sample of a chemical formula Ca_0.8Ba_0.2Cu₃Ti₄O₁₂ (CBCTO-20) ceramic has been fabricated by a low-cost ceramic technology. The structural analysis reveals that the studied compound has cubic crystal symmetry at room temperature. The surface micrograph of the pellet sample, recorded at room temperature using scanning electron microscope (SEM), shows a high-density sample. Attempts have been made to study the (a) effect of microstructures containing grains, grain boundaries, and electrodes in impedance and capacitive characteristics, (b) relationship between structural–physical properties and (c) nature of the relaxation mechanism of the prepared samples. The electrical behavior of the sample is analyzed by using complex impedance and modulus data. (P ∼ E) loop of the CBCTO bulk sample showed lossy behavior. The utilization of TiO₂ and CuO₂ nano-size powder at the beginning stage with micron size CaCO₃ and BaCO₃ powder promote the kinetics of rapid solid-state reaction at the microscopic level. This compound shows a remarkable temperature stable relative dielectric properties and low tangent loss, thus becoming a potential candidate for high-temperature dielectric applications.

Keywords:

• Conductivity
• dielectric properties
• ferroelectric polarization
• supercapacitor
• X-ray diffraction

Acknowledgments

The author (MS) acknowledges to the Director, Institute of Materials Science, Bhubaneswar, India, for providing experimental facilities and the laboratory assistant Mr. M. S. Beg for his support.