A structural transition of Ba6Ti17O40/BaTiO3 interfaces from faceted to rough was induced by reducing O partial pressure in the atmosphere. As the O partial pressure decreased, the number densities of {111} twins and abnormal grain decreased. TEM observation showed that the twin formation was governed only by the faceting of the interface. Experimental evidence of {111} twin-assisted abnormal growth of faceted BaTiO3 grains was also obtained.

Effect of Ba6Ti17O40/BaTiO3 Interface Structure on {111} Twin Formation and Abnormal Grain Growth in BaTiO3. Y.I.Jung, B.K.Lee, S.J.L.Kang: Journal of the American Ceramic Society, 2004, 87[4], 739