Study on structural, dielectric, and thermal behavior of CaCu₃Ti₄O₁₂@CoFe₂O₄ composites

By tailoring and optimizing the structure of core or shell material, complete alteration of properties of the material can be obtained. Herein, we have reported synthesis of CaCu₃Ti₄O₁₂@CoFe₂O₄ particles through the chemical co-precipitation route. CaCu₃Ti₄O₁₂@CoFe₂O₄ particles consist of CaCu₃Ti₄O₁₂ (~ 200 nm) as a core and CoFe₂O₄ as a shell of 2.5 nm. The prepared composites are characterized with appropriate characterization tools. The morphological results confirm the proper formation of core shell structure where CaCu₃Ti₄O₁₂ and CoFe₂O₄ act as a core and shell, respectively. The greater CCTO content composites exhibited promising relative permittivity of 8.2 × 10³ at 700 °C sintering temperature (8 h) at frequency 40 to 8 MHz. When CaCu₃Ti₄O₁₂@CoFe₂O₄ undergoes heat treatment, it leads to the removal of oxalic acid. However, a weight loss of 8.3% is obtained for CCTO-coated composites that is quite low as compared to ~ 11% weight loss obtained in pristine CFO. The removal of organic groups significantly contributed to the increase in dielectric properties. These results imply that the development of CaCu₃Ti₄O₁₂@CoFe₂O₄ core shell structure paves the wave for high-performance devices.