Microstructure and dielectric properties of CCTO glass-ceramic prepared by the melt-quenching method

In this work, CaCu3Ti4O12 (CCTO) glass-ceramic was prepared by using the melt-quenching method followed by a two-step heat treatment. The prepared glass frits with the chemical composition of 24SiO(2)-65PbO-3K(2)O-7B(2)O(3)-1ZnO (wt. %) were mixed with 32, 34 and 38 wt % of CCTO including 14.03 CaO-29.66 CuO-56.31 TiO2 (wt. %) and melted at 1070-1090 degrees C. The glass with 32 wt % of CCTO, which was XRD amorphous, was selected as the final composition. The heat treatment conditions were found to be 6 and 2 h at 468 degrees C and 830 degrees C, respectively. The faceted crystals of CCTO, two solid-solution of (Pb1-xCax)TiO3, and CaTiO(SiO4) were formed in the glassy matrix during the crystallization based on the studies related to XRD, SEM, EDS, and elemental mapping in the glass-ceramic. The measured dielectric constant of the glass was 16.3 at 1 MHz, which reached 41.2 after the heat treatment process, and the value of the tans increased from 4.6x10(-5) to 0.012.