Domain switching in lead magnesium niobate-lead titanate polycrystalline sheets at single grain level.

The authors provide direct evidence of non-180° domain switching in the piezoelectric response of substrate-free 40 μm thick polycrystalline [Pb(Mg1/3Nb2/3)O3]0.63(PbTiO3)0.37 (PMN-37PT) sheets under dc electric fields through piezoresponse force microscopy (PFM) at the single grain level. The sheet’s polarization preferred pointing in the planar direction which was switched to the normal direction at electric field ranging between 1.3 and 1.9 kV/cm. An independent d31 measurement of PMN-37PT sheets deduced from the axial tip displacement measurements of a 4 mm long PMN-PT/copper cantilever showed enhanced d31 values that peaked at –2700 pm/V in the same range of electric field, consistent with the PFM observation. [ABSTRACT FROM AUTHOR]