Interweaving domain configurations in [001]-poled rhombohedral phase 0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 single crystals

Domain structures in [001]-poled rhombohedral phase 0.68Pb(Mg1/3Nb2/3)O-3-0.32PbTiO(3) single crystals have been investigated using polarized light microcopy. It was found that the observed domain structures are quite different from those previously assumed four domain states with cross intersecting 71degrees charged domain walls. The pattern can be interpreted as interweaving of two types of twins in three dimensions. Each local twin pattern contains only two domains with a 109degrees charged domain wall in either [110] or [1 (1) over bar0]. The stacking of two 90degrees rotated twins produces a cross-hatching pattern for transmission optical microscope and an effective 4mm macroscopic symmetry. The pattern becomes simple twins when the imaging is focused at different depth. The domain size is 1-2 mum in all the samples observed and the twin layer thickness is about 50-100 mum. (C) 2003 American Institute of Physics.