Lamellar and bundled domain rotations in barium titanate
Jane A. Howell, Mark D. Vaudin, Lawrence Henry Friedman, Robert F. Cook
Cross-correlation of electron backscatter diffraction patterns has been used to generate rotation maps of single crystals of tetragonal barium titanate (BaTiO3) containing multiple lamellae and bundles of 90 domains. Rotation measurement angular resolutions of 0.1 mrad (0.006) and spatial resolutions of 30 nm are demonstrated on structures with approximately 1 m domains extending over 10s of m. The measurements demonstrated considerable microstructural dependence: c domains, with polarization perpendicular to a free surface, exhibited little within-domain rotation variation while a domains, with polarization parallel to the surface, exhibited considerable within-domain variation, particularly in the larger lamellar domain structure. In both lamellar and bundled structures, the maximum a-c between- domain rotation was approximately equal to the value r 0.63 ( 11 mrad) predicted by a rigid rotation of tetragonal BaTiO3 unit cells across the domain boundary. However, in both structures there was gradual variation in rotation throughout, especially adjacent to domain boundaries, suggesting that a rigid rotation model predicts too abrupt a unit cell and polarization rotation. A new BaTiO3 compound defect was identified through association with a double integral surface rotation 2r. The double rotation is indicative of a low-angle grain boundary terminating at a surface by a confined 90 domain.
Journal of Materials Science
electron backscatter diffraction, barium titanate, rotation, domain