Orientation, stress, and strain in an (001) barium titanate single crystal with 90° lamellar domains determined using electron backscatter diffraction

The orientation, stress, and strain in a single crystal of barium titanate (BaTiO3), containing relatively large (0.5–14.5 μm), parallel, lamellar domains, have been determined and mapped using electron backscatter diffraction (EBSD). The strain distribution in the single crystal was determined using cross-correlation analysis of the EBSD patterns. Strain in the (001) single crystal was dominated by strain in the minority a-domain bands with peak values of −0.006 determined in the surface plane, perpendicular to the intersection of the domain walls with the crystal surface, compared to +0.002 in the same direction for the majority c-domains. The out-of-plane strains were negatively correlated with the in-plane strains and were about a factor of two smaller. The experimentally determined strains peak at domain boundaries and suggest a contraction of the c-axis and an expansion of one of the a-axes as the domain wall is approached. The ratios of the in-plane and out-of-plane strains were consistent with the bulk elastic constants of BaTiO3. Stress values determined from the strains and the elastic constants peaked at 400 MPa.