[101]-Oriented Pb(Mg1/3nb2/3)O-3-Pbtio3 Single Crystals Under Electric Loadings: Polarization Rotation Linking M-B, O, And R Phases

We report on the existence of monoclinic (M-B), orthohombic (O), and rhombohedral (R) phases in [101]-oriented 74Pb(Mg1/3Nb2/3)O(3-)26PbTiO(3) (PMN-26PT) single crystals under electric loadings. Before electric loadings, the [101]-oriented PMN-26PT single crystal is composed of R and monoclinic phases. Both M-B and R phases are revealed after being poled in the [101] direction. When the single crystal is subjected to bipolar cyclic electric field, an M-B phase bridges the reversal of domains of R phase. Reversal of the domains of M-B phase is achieved by either 180 degrees domain switching or non-180 degrees domain switchings. Under static electric field, polarization rotation from R to M-B again occurs, and as the field increases, phase transition from M-B to O phase occurs. The O phase is metastable because it tends to change back to M-B phase after the removal of electric field. The findings are of importance for understanding the microstructure characteristics of [101]-oriented PMN-PT single crystals that show the ultrahigh piezoelectric performances at the morphotropic phase boundary.