Multi‐scale domain structure observation and piezoelectric responses for [001]‐oriented PMN‐33PT single crystal

Multiple phase coexistence contributes to the extraordinary piezoelectric behavior of (1‐x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN–xPT) near the morphotropic phase boundaries (MPBs). By incorporating an optical path of crossed polarized light (PLM) into the commercialized Piezoelectric Force Microscope (PFM) (named as PLM‐PFM system), in situ domain structure observation from micro‐ to nanoscale, as well as measurement of the piezoelectric behavior for individual domains can be realized. For [001]‐oriented single crystal of 67Pb(Mg1/3Nb2/3)O3‐33PbTiO3 (PMN‐33PT), fine domain boundary structures of rhombohedral (R), tetragonal (T), and monoclinic (M) phases are revealed. Measurements of the electric field‐induced displacement as a function of the applied DC electric field (VDC) are performed for domains with different polarization vectors. Values for the electric field‐induced displacement are in descending order for c‐domains of the M, R, and T phases. For an individual phase of T or M, the displacement increases when the angle between the polarization vector and the applied electric field decreases. The multi‐scale perspective of the domain structures and the corresponding piezoelectric response helps in understanding the ultra‐high piezoelectric performance for PMN‐PT single crystals near MPB. Multiscale domain structure observation and piezoelectric response for PMN‐PT ferroelectric single crystal.