A Novel One‐Step Flame Synthesis Method for Tungsten‐Doped CCTO

Abstract

An efficient synthesis is used for the first time to prepare CaCu 3 Ti 4− x W x O 12 ( x = 0.01, 0.03, and 0.05) electroceramics for energy storage capacitors. CaCu 3 Ti 4− x W x O 12 ceramics are synthesized via flame synthesis of metal nitrates precursors in nonaqueous solution using cheap, stable, and insoluble solid TiO 2 powder. The pathway yielded a CaCu 3 Ti 4 O 12 (CCTO) phase with the traces of CuO and CaTiO 3 sintered at 1050°C for 30 h. The SEM micrograph shows the grains with smooth surfaces associated with cubical appearance and the size range of 1.5–7, 2.0–7.5, and 2.0–8.0 μm for CCTWO01, CCTWO03, and CCTWO05, respectively. The EDX and XPS analyses show the presence of Ca, Cu, Ti, W, and O elements confirming the purity of these ceramics. The complex impedance and modulus ( M ) spectroscopy show that the dielectric constant (ε r ) values of the W‐doped CCTO were dominantly affected by the electrical properties of the grain boundary, which is also evident from the SEM micrographs. The grain‐boundary resistance decreased with increasing tungsten content. The activation energies for the grain boundaries were calculated from the impedance and modulus data using the slope of the ln τ versus 1/ T and were found to be in the range 0.62–0.67 eV.