Dielectric and energy storage behavior of CaCu3Ti4O12 nanoparticles for capacitor application

Abstract

Nanoparticles of CaCu3Ti4O12 (CCTO) has been synthesized by using sol- gel method. The X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) have respectively been used to confirm phase purity and determination of CCTO nanoparticles. The size of most of CCTO particles is lying in the range 50–60 nm. The dielectric constant and tangent loss of CCTO at 1 kHz has been found to be ~ 7790 and ~ 0.096 respectively. The breakdown electric field and nonlinear coefficient are found as ~ 4400 V/cm and ~ 6.3 respectively. High value of breakdown electric field and dielectric constant are respectively attributed to: (i) formation of large number of energy bands in grain boundary that traps the electrons at grain/grain boundary interface and, (ii) grain boundary inter barrier layer capacitance (IBLC). High dielectric constant and high breakdown electric field materials are very good for the pulsed power application. Discharge energy density and discharging time are obtained as ~ 7 J/cc and ~ 0.34 ms respectively. Therefore, CCTO exhibits high dielectric constant and high breakdown electric field along with very good capacitive behavior.