The epitactic growth of calcium hexaluminate (CA6) on the basal plane of alumina was studied. Two distinctly different orientational relationships were found. The first could be described as being perfect hexagon-on-hexagon epitaxy with (11•0)CA6||(10•0)alumina and (00•1)alumina||(00•1)CA6. This relationship was associated with a 1.1% lattice misfit in the substrate plane. The misfit was accommodated at the interface by an hexagonal network of misfit dislocations. In the case of the second relationship, the CA6 grains were rotated around the substrate normal, and could be explained by the coincident-site lattice model for phase boundaries.

M.P.Mallamaci, K.B.Sartain, C.B.Carter: Philosophical Magazine A, 1998, 77[3], 561-75