Dielectric Response and Low Dielectric Loss of Gadolinium-Doped CaCu3Ti4O12 Ceramics Processed Through Conventional and Microwave Sintering

Gadolinium-doped (CaCu3Ti4O12/CCTO)(x) ceramics were fabricated using conventional (CS) and microwave sintering (MWS) at x = 0.1, 0.2 and 0.3. The green compacts were sintered at 1100 degrees C via muffle and microwave furnace at 5 degrees C min(-1)/12 h and 50 degrees C min(-1)/30 min, respectively. A single pure cubic phase of CCTO for MWS and minor secondary phases for CS were revealed by x-ray diffraction (XRD) patterns. Scanning electron microscope (SEM) images showed a reduction in grain size from similar to 20.04 +/- 8.43 mu m to similar to 17.52 +/- 7.77 mu m and similar to 1.99 +/- 0.44 mu m to similar to 1.32 +/- 0.27 mu m for both CS and MWS. The charge carrier hopping between Cu+ and Ti3+ was probed using x-ray photoelectron spectroscopy (XPS), which confirmed the conductivity of grains and internal barrier layer capacitance (IBLC) effect. Broadband dielectric spectrometer findings revealed a dielectric constant of e > 10(4) at 10 Hz and e > 10(3) at 100 kHz for CS at x = 0.2 and e > 10(2) at 10 Hz (x <= 0.2) for MWS. A very minimal tan delta of 0.08 (x = 0.2) was recorded at 100 kHz.