New approach for synthesis of nano-sized CaCu₃Ti₄O₁₂ powder by economic and innovative method

Abstract

In this work, calcium carbonate (CaCO₃), copper oxide (CuO) and titanium oxide (TiO₂) were used as precursors to synthesize nano-sized calcium copper titanate CaCu₃Ti₄O₁₂ (CCTO) powder using environmental friendly and modified sonochemical-assisted process. The precursor mixtures were sonicated at 80 °C for 4 h to get a fully precipitated and homogenous product. A pure phase of CCTO powder was obtained at 900 °C. Various techniques were employed to study the phase formation and structural aspects of the calcined CCTO such as XRD, FTIR, HRTEM, TGA and dielectric spectroscopy. The XRD results confirm the formation single phase with cubic structure of the CCTO phase. The absorption bands in FTIR at 400–700 cm⁻¹, which arise from the mixed vibrations of CuO₄ and TiO₆ groups, are prevailing in the CCTO structure. Moreover, the HR-TEM micrographs reveal a highly oriented single cubic crystal structure of particle size ~ 4.78 nm. In addition, the dielectric study discloses that the dielectric constant ε′ increased with increasing the calcination temperature up to 900 °C escorted by a decrease of loss factor (tanδ). This can be attributed to the formation of pure CCTO phase and the highly dense microstructure at high temperatures. Giant dielectric constant ε′ up to (10⁶–10⁵) exhibited at low frequency (1–1000 Hz). It is deduced that the optimum calcination temperature of the prepared CCTO must not exceed the temperature range (800–900 °C). Furthermore, the prepared CCTO nanopowder is a promising material for energy storage applications.