Investigation of the Microstructure and Chemical Composition of CaCu₃Ti₄O₁₂ Multilayer Elements using SEM, EDS, and XPS

Abstract

In this paper the microstructure and chemical composition of CaCu3Ti4O12 multilayer elements fabricated using low temperature cofired ceramics procedure were characterized by scanning electron microscope, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The multilayer elements were obtained in the process encompassing: tape casting, laser cutting, screen printing, isostatic lamination and cofiring of ceramic tapes with internal conductive films at 940 • C. The compatibility of CaCu3Ti4O12 with three commercial Ag and Ag-Pd thick film pastes was confirmed. The results of scanning electron microscope and energy dispersive spectroscopy analysis revealed close to the stoichiometric composition of CaCu3Ti4O12 grains and significant enrichment in oxygen of grain boundaries. X-ray photoelectron spectroscopy studies showed that main oxidation states of the component elements were Cu 2+ , Ti 4+ , and Ca 2+ .

Nano-Sized Calcium Copper Titanate for the Fabrication of High Dielectric Constant Functional Ceramic–Polymer Composites

“…In Figure 6 , the peak of Cu 2 p 2/3 spectra can be divided into three peaks by Gaussian–Lorentzian profile fitting, which correspond to Cu + , Cu 2+ , and Cu 3+ ions from low to high binding energies. According to the literature, [ 37 , 38 , 39 , 40 ], the existence of Cu + , Cu 2+ , and Cu 3+ may be ascribed to the semiconductivity of grains due to the hopping of charge carriers. In addition, this semiconductivity was easy to be detected in the titanate-based materials due to the small but significant amount of oxygen loss at high temperatures (>1000 °C) [ 23 , 36 , 41 , 42 ].…”