Effect of oxygen sintering on the structural and electrical properties of KNN ceramics

Single perovskite phase of K0.5Na0.5NbO3 (KNN) system was obtained at low calcination temperature (450 °C) by combustion method using urea as fuel. The sintering of the KNN sample was performed at 1120 °C for 2 h in the oxygen rich environment. SEM micrograph showed the dense and non-uniform distribution of grains with grain size ∼1.45 μm. The experimental density of the oxygen sintered KNN samples was found to be ∼4.398 g/cc, which is higher than the same system sintered in air by mixed oxide method.