Synthesis of CaCu3Ti4O12 utilizing eggshell waste as a calcium source: Structure, morphology, and dielectric properties

Calcium copper titanate (CaCu3Ti4O12, CCTO) has been synthesized utilizing eggshell waste as a source of calcium through the hydrothermal route, followed by annealing treatment at temperatures 950°C and 1050°C. The sample with annealing temperatures of 950°C and 1050°C is named CTO-A and CCTO-B, respectively. The structure, microstructure, and dielectric properties of CCTO samples were investigated. The X-ray diffraction analysis results confirmed that the pure phase of CCTO has been successfully synthesized as identified in the diffraction pattern. The average crystallite size of CCTO is quite large due to annealing at high-temperature. The morphology of CCTO by electron microscopy investigation showed the grains tends to agglomerate as the annealing temperature increases due to the solid-state diffusion. Dielectric property investigation showed the CCTO samples have a high dielectric constant at low frequencies and decrease with increasing frequency. Sample CCTO-A annealed at 950oC has a higher dielectric constant than sample CCTO-B annealed at 1050oC, otherwise, it has a lower tangent loss than the sample CCTO-B.