Optimization of dielectric phenomenon in 0.8[(1-x)SrCoO2.29 + xCr2FeO4] + 0.2PZT tri-phase composites

Abstract

Composite materials are emerging and have potential to revolutionize the modern technology. In this work, a series of tri-phase composite materials having the chemical formula; 0.8[(1-x) SrCoO2.29+xCr2FeO4] + 0.2PZT, is synthesized to explore their energy storage capability. In this series, SrCoO2.29 and Cr2FeO4 ceramics are synthesized by using a sol-gel auto-combustion process while PZT is prepared by the solid-state method. The XRD analysis confirmed the formation of cubic crystal structure of the SrCoO2.29 and Cr2FeO4 and the rhombohedral phase of PZT. The SEM images exhibited an increase in average grain size with the incorporation and increasing contents of Cr2FeO4. The presence of all constituting elements with the exact stoichiometric ratio is validated through EDX analysis. Wide-range frequency-dependent dielectric behavior showed a dramatic fall in dielectric constant with increasing frequency. A same frequency dependent behaviour of ε'' and tanδ is witnessed as that of ε'. The investigation of electric modulus reveals that in the low-frequency region it possesses a trivial value which became significantly large with the increase of frequency. The presence of a relaxation peak in the plot of the imaginary part of the electric modulus plays a decisive role to distinguish the small and large range hopping mechanism. The complex impedance analysis revealed different electroactivity of composite material in the different frequency domains which made them viable for advanced energy storage devices working in the vast frequency range.