Journal of Materials Science, Vol.55, No.19, 8041-8049, 2020
In situ observation of two-step 90 degrees domain reversal with different characteristics in PMN-38%PT single crystal
Domain structures and their reversal process of (010)-cut Pb(Mg1/3Nb2/3)O-3-38%PbTiO3 single crystal were in situ investigated under varying electric fields by polarized light microscope. High-density needlelike ferroelectric microdomains were observed in macrodomains. When an electric field along  was applied on the crystal, macrodomain walls keep immobility, while the vertical microdomains first flip to the transverse direction and then to the vertical direction again. The two-step 90 degrees domain reversal exhibits quite different characteristics. The first step finished quickly at a low electric field and in a narrow electric field range, leading to high polarization current. The second step happened slowly at the high electric field and in a wide electric field range, and no obvious polarization current was observed. Two-step domain reversal mechanism was investigated, and our findings will help in understanding the excellent properties of relaxor Pb(Mg1/3Nb2/3)O-3-PbTiO3 single crystal.