Low-temperature synthesis of CaCu3Ti4O12 powders, ceramics and thin films via an organic solution

Abstract

The giant-dielectric-constant material CaCu3Ti4O12 (CCTO) was synthesized via an organic solution containing stoichiometric amounts of the metal cations, which is done at lower temperature and shorter reaction time than the conventional solid-state reaction. A stable solution was prepared by dissolving calcium nitrate, copper nitrate, and tetrabutyl titanate in grain alcohol. CCTO powders, ceramics and thin films were synthesized via the solution. The phases, microstructures, and dielectric properties of samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and dielectric spectroscopy. XRD results identify both samples as single phase CCTO. The CCTO ceramics has a low-frequency permittivity of 3.5 × 104. The CCTO thin films has a low-frequency permittivity of 3.1 × 104. Both the CCTO ceramics and CCTO thin films exhibit two dielectric relaxations at room temperature. The low leakage current density of CCTO thin films shows that it is suitable for memory device applications.