Microstructure Control of Barium Titanate - Potassium Niobate Solid Solution System Ceramics by MPB Engineering and Their Piezoelectric Properties

KBaTiNbO6, i.e., 0.5BT-0.5KN complete solid solution ceramics and barium titanate (BaTiO3, BT) - potassium niobate (KNbO3, KN) system (0.5BT-0.5KN) ceramics with various microstructures were prepared by conventional sintering method and two-step sintering method. The 0.5BT-0.5KN with diffusion of BT and KN completely were paraelectrics. Their microstructures were investigated using X-ray diffraction (XRD) measurement and scanning electron microscopy (SEM). KBaTiNbO6 at room temperature was assigned to cubic Pm3m symmetry. For the 0.5BT-0.5KN patially solid solution system ceramics, the control of the interface area between two phases was important to enhance piezoelectric property. Their piezoelectric property was measured, and the apparent piezoelectric constant d33* increased with increasing interface area.