In situ transmission electron microscopy studies of electric-field-induced phenomena in ferroelectrics

High electric fields were delivered to specimens during imaging in the transmission electron microscopy (TEM) chamber to reveal details of electric field-induced phenomena in ferroelectric oxides. These include the polarization switching in nanometer-sized ferroelectric domains and the grain boundary cavitation in a commercial lead zirconate titanate (PZT) polycrystalline ceramic, the domain wall fracture in a Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) single crystal, and the transformation of incommensurate modulations in Pb(0.99)Nb(0.02)[(Zr(1-x)Sn(x))(1-y)Ti(y)](0.98)O(3) (PZST100x/ 100y/2) polycrystalline ceramics. In the PZT ceramic, a cavitation process was uncovered for the electric field-induced intergranular fracture. In the ferroelectric single crystal, a preexisting crack was observed to deflect and to follow a 90 degrees domain wall, indicating the presence of severe incompatible piezoelectric strains at the, domain wall. In the antiferroelectric PZST ceramics, the electric field-induced antiferroelectric-to-ferroelectric phase transformation was accompanied with the disappearance of incommensurate modulations.