fig4
From: Microstructure and piezoelectric properties of AC poled relaxor-PbTiO3 perovskite single crystals

Figure 4. (A) poling wave forms; (B) DEP SEM image; (C) OPP-DCP SEM image; (D) OPP-ACP SEM image. DEP: depolarization; SEM: scanning electron microscopy; OPP: optimum polarization; ACP: alternating-current poling. DCP: direct-current poling.