Two-dimensional orientation in Bi₄ Ti₃ O₁₂ prepared using platelet particles and a magnetic field

Tailoring the crystallographic orientation in piezoelectric ceramics is very useful for improving their properties. Orientation in ceramics can be controlled by templated grain growth, hot forging, etc. We have focused on using a strong magnetic field for the crystallographic orientation even in diamagnetic ceramics. In a previous study, although only a one-directional orientation could be controlled by these methods, it was difficult to control the multi-axis orientation in the ceramics. In this study, we demonstrated that alignments of the c-axis and the <100> axis in Bi₄Ti ₃O₁₂ piezoelectric ceramics were controlled by using a strong magnetic field as well as platelet particles. We also estimated the degree of orientation by an electron back scattering diffraction analysis. When the magnetic field was applied to the platelet particles, appropriately 80% of the grains were aligned with the tilt angle made by the c-axis and the vertical direction less than 10° and 73% of grains were oriented with the angle between the <100> axis and the magnetic field less than 10°.