Domain structure of 0.8Pb(Mg1/3Nb2/3)O3-0.2PbTiO3 studied by piezoresponse force microscopy

High-resolution domain studies have been performed on 0.8Pb(Mg 1 / 3 Nb 2 / 3 )O 3 -0.2PbTiO 3 (0.8PMN-0.2PT) single crystals via piezoresponse force microscopy (PFM). A complex structure consisting of micron-size domains comprising embedded nanodomains of opposite orientation has been revealed on the (100) surface of the crystals. The existence of such peculiar patterns is related to the combination of ferroelectric and relaxor properties in this particular composition. The micron-size areas represent "normal" ferroelectric domains, while embedded nanodomains are attested to polar clusters that might exist in relaxors far above the Curie point (T C ) and to he preserved below T C due to local random fields. The evolution of domain structure of 0.8PMN-0.2PT crystals is studied under increasing temperature.