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

Abstract

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.