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

Bi4Ti3O12 (BTO) powders were synthesized using soft combustion techniques, specifically known as Solution Combustion Synthesis (SCS) and Low-temperature Combustion Synthesis (LCS). XRD results showed that the single phase BTO was obtained following calcinations at 800oC for the sample prepared using SCS; compared to after combustion, for the sample prepared using LCS. The TG/DTA showed a combustion temperature of around 252 - 280oC, which became stable with a single phase BTO at 500oC and above. Sintering was carried out at 1,100oC 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%, εr = 320 - 360, tan δ = 0.03 - 0.1, Pr = 6.8 μC/cm2, and Ec = 20 kV/cm. Meanwhile, the bulk ceramics prepared using LCS showed plate-like grains, strong c-preferred grain orientation, a relative density of 83%, εr = 143 - 195, tan δ = 0.01 - 0.38, Pr = 5.9 μC/cm2, and Ec = 30 kV/cm.