Microwave synthesis and sintering characteristics of CaCu 3Ti4O12

Abstract

CaCu3Ti4O12 (CCTO) was synthesized and sintered by microwave processing at 2-45 GHz, 11 kW. The optimum calcination temperature using microwave heating was determined to be 950°C for 20 min to obtain cubic CCTO powders. The microwave processed powders were sintered to 94% density at 1000°C/60 min. The microstructural studies carried out on these ceramics revealed the grain size to be in the range 1-7 μm. The dielectric constants for the microwave sintered (1000°C/60 min) ceramics were found to vary from 11000-7700 in the 100 Hz-100 kHz frequency range. Interestingly the dielectric loss had lower values than those sintered by conventional sintering routes and decreases with increase in frequency. © Indian Academy of Sciences.