Cc. Chou et Cm. Wayman, DETERMINATION OF DISPLACEMENT VECTOR ON 180-DEGREES DOMAIN BOUNDARY AND POLARIZATION ARRANGEMENTS IN LEAD TITANATE CRYSTALS, Journal of materials research, 12(2), 1997, pp. 457-466
180 degrees domain boundaries in flux-grown lead titanate single cryst
als show intriguing domain boundary extreme fringe contrast using tran
smission electron microscopy. Symmetrically distributed domain boundar
ies with alternate contrast have been observed, indicating that opposi
te displacement vectors exist one by one at boundaries, If appropriate
reflection vectors were employed, an inclined domain boundary shows r
eversed fringe contrast. An analysis based upon the two-beam dynamical
theory and a rule similar to stacking-fault contrast analysis was emp
loyed to predict the geometric configuration of a 180 degrees domain b
oundary using the extreme fringe contrast (EFC) behavior. Appropriatel
y choosing reflection Vectors and utilizing the EFC reversal, a displa
cement vector as well as the polarization vector arrangement across a
180 degrees domain boundary can be unambiguously identified, Employing
the information derived from diffraction patterns and a tilting exper
iment across a nearby 90 degrees boundary, the whole polarization conf
iguration can be uniquely determined.