E-field-induced polarization rotation in Pb(Mg[sub 1/3]Nb[sub 2/3])[sub 1-x]Ti[sub x]O[sub 3] crystal.

A sequence of field-induced phase transformations was observed by means of a polarizing microscope on a (111)-cut single crystal Pb(Mg[sub 1/3]Nb[sub 2/3])[sub 0.67]Ti[sub 0.33]O[sub 3] at room temperature with an electric field applied along the [111] direction. As electric field increases, polarizations of the rhombohedral R domains whose polar directions are not along [111] rotate first toward a tetragonal T phase associated with 90° domain walls. Then the crystal gradually reaches total optical extinction for all polarizer angles at 12 kV/cm, indicating a single [111] rhombohedral R[sub 111] domain with polarization aligned with the electric field. These field-induced phase transformations are irreversible and proceed most likely through M[sub A]-type monoclinic distortions, i.e., R→M[sub A]→T→M[sub A]→R[sub 111]. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]