6533b7d5fe1ef96bd1264f6d

RESEARCH PRODUCT

Forming pressure dependence of the ferroelectric domain structure in green barium titanate pellets

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Abstract Modifications of the X-ray diffraction line profiles by die pressing of fine grained powders of barium titanate have been studied. Two main parameters have been considered: the forming pressure and the mechanical characteristics of the binder. The higher the forming pressure, the greater the modifications of the line profiles. Furthermore, the phenomena seems to be related to pressing only; no significant effect related to the nature of the binder has been shown. The modifications of the diffraction line profiles are interpreted by considering a reduction of the size of the ferroelectric domains during pressing. In order to confirm this interpretation, the behaviour of the domain structure of a BaTiO 3 single crystal under local compression has been studied. The average size of the domain is dramatically reduced by applying local pressure. Moreover, the domain structure modifications produced by the high stress state are largely preserved under a rather low residual pressure. There is a kind of hysteresis as a function of the pressure. This observation may explain the remanent modifications of the line profiles recorded after pressure relaxation.