Microwave synthesis and sintering characteristics of CaCu3Ti4O12

CaCu3Ti4O12 (CCTO) was synthesized and sintered by microwave processing at 2 center dot 45 GHz, 1 center dot 1 kW. The optimum calcination temperature using microwave heating was determined to be 950 degrees C for 20 min to obtain cubic CCTO powders. The microwave processed powders were sintered to 94% density at 1000 degrees C/60 min. The microstructural studies carried out on these ceramics revealed the grain size to be in the range 1-7 mu m. The dielectric constants for the microwave sintered (1000 degrees C/60 min) ceramics were found to vary from 11000-7700 in the 100 Hz-00 kHz frequency range. Interestingly the dielectric loss had lower values than those sintered by conventional sintering routes and decreases with increase in frequency.