Electric and dielectric behavior of CaCu 3Ti 4O 12-based thin films obtained by soft chemical method

Abstract

CaCu 3Ti 4O 12 (stoichiometric) and Ca 1.1Cu 2.9Ti 4O 12 (non-stoichiometric) thin films have been prepared by the soft chemical method on Pt/Ti/SiO 2/Si substrates, and their electrical and dielectric properties have been compared as a function of the annealing temperature. The crystalline structure and the surface morphology of the films were markedly affected by the annealing temperature and excess calcium. The films show frequency-independent dielectric properties at room temperature which is similar to those properties obtained in single-crystal or epitaxial thin films. The room temperature dielectric constant of the 570-nm-thick CCTO thin films annealed at 600 °C at 10 kHz was found to be 124. The best non-ohmic behavior ( α = 12.6) presented by the film with excess calcium annealed at 500 °C. Resistive hysteresis on the I– V curves was observed which indicates these films can be used in resistance random access memory (ReRAM).