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

The authors provide direct evidence of non-180 degrees domain switching in the piezoelectric response of substrate-free 40 mu m thick polycrystalline [Pb(Mg1/3Nb2/3)O-3](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 d(31) measurement of PMN-37PT sheets deduced from the axial tip displacement measurements of a 4 mm long PMN-PT/copper cantilever showed enhanced d(31) values that peaked at -2700 pm/V in the same range of electric field, consistent with the PFM observation.