Crystallographic correspondences and variant selection in zirconia-based shape memory ceramics: Insights from EBSD mapping

Previous studies of the martensitic transformation in zirconia ceramics have suggested a preference for specific lattice correspondences based on lattice invariant shear minimization. However, these conclusions have largely been drawn from limited datasets, primarily obtained via transmission electron microscopy . In this work, we employ advanced Electron Backscatter Diffraction (EBSD) methods to statistically analyze the distribution of martensite variants in ZrO₂-CeO₂ alloys. By leveraging novel techniques that resolve the long-standing pseudosymmetry problem in tetragonal zirconia , we demonstrate the simultaneous presence of all twenty-four possible martensitic variants, encompassing three lattice correspondences and two distinct orientation relationships. Our findings challenge the conventional assumption that a single dominant correspondence governs the transformation, and reveal a significant role for self-accommodation mechanisms in variant selection. These results offer new insights into the crystallographic factors governing martensitic transformations in zirconia and open new pathways for microstructural design in shape memory ceramics.