Two‐Dimensional Orientation in Bi₄Ti₃O₁₂ Prepared Using Platelet Particles and a Magnetic Field

Abstract

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 Bi 4 Ti 3 O 12 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°.

Advanced control of crystallographic orientation in ceramics by strong magnetic field

“…Figure 10 shows the {001} and {100} pole figure on the T plane perpendicular to the gravity and parallel to the magnetic field. 54) In the {001} pole figure, one strong peak is at the center, indicating that the c-axis is aligned perpendicular to the T plane. In the {100} pole figure, four strong peaks were on the S1 and S2 planes parallel and perpendicular to the magnetic field, indicating that the ©100ª axis was aligned parallel to the magnetic field and showed a two-dimensional orientation.…”

Texturing of hydrothermally synthesized BaTiO3 in a strong magnetic field by slip casting

“…Texture of ceramic materials with interesting properties in a strong magnetic field has gained much attention recently. [2,3,5,8,9,12] The very low diamagnetic susceptibilities ( ) of ceramic materials did not make them very attractive for magnetic studies. However, the development of magnets with strong fields by the use of superconducting materials made the study of feeble diamagnetic ceramics much more appealing.…”

Triaxial Crystalline Orientation of MgTi2O5 Achieved Using a Strong Magnetic Field and Geometric Effect

“…Thus, we tried to control the multiaxial orientation using both geometric effect and a magnetic field. These two effects are expected to control different axes of orientation in case the easy magnetization axis is different from the oriented axis by the geometric effect . We reported that bi‐axial orientation in Bi 4 Ti 3 O 12 could be achieved by slip casting of the platelet particles in a strong magnetic field where the c ‐axis of the platelet particle was aligned by the force of gravity, and the a ‐ and b ‐axes were aligned by the magnetic field.…”