Optical Micoscope Study of 90° Ferroelectric Domain in 67 Pb(Mg_(1/3)Nb_(2/3)) O_3-33PbTiO_3 Solid Solution Single Crystal

°Ferroelectric domains in 67 Pb(Mg_(1/3)Nb_(2/3)) O_3-33PbTiO_3 single crystal were observed at room temperature by using crossed polaxized light microscope(PLM). Ferroelectric domain structures depend on the quality of single crystals. Large homogeneous domains of 2～3mm exist in optical transparent single crystals. Large domains with different polarization orientation overlap to form opaque regions. {110} type 90° banded a-a domain with 90° sub-domain can be observed in translucent crystals. The dimension of banded twin is about 0.1mm. As a result, surface relief appears on translucent crystal surface. The mechanism of forming these domains was discussed.