Soft combustion technique: Solution combustion synthesis and low-temperature combustion synthesis; to prepare Bi4Ti3O12 powders and bulk ceramics

Bi4Ti3O12 (BTO) powders were synthesised using soft combustion techniques (solution combustion synthesis (SCS) and low-temperature combustion synthesis (LCS)). XRD showed that single phase BTO was obtained following calcination at 800 C for the sample prepared using SCS, compared to after combustion for the sample prepared using LCS. TG/DTA showed a combustion temperature of around 252-280 C, which became stable with single phase BTO at 500 C and above. Sintering was carried out at 1100 C for 3 h, to determine the microstructures, grain orientation, relative density, dielectric and ferroelectric properties of the bulk ceramics. It was found that the bulk ceramics prepared using SCS exhibited elongated-like grains, strong (117)-preferred grain orientation, a relative density of 93.3%, epsilonr = 320-360, tan delta = 0.03-0.1, Pr = 6.8 microC/cm2, and Ec = 20 kV/cm. Bulk ceramics prepared using LCS showed plate-like grains, strong c-preferred grain orientation, a relative density of 83%, epsilonr = 143-195, tan delta = 0.01-0.38, Pr = 5.9 microC/cm2, and Ec = 30 kV/cm.