LONG-TIME PRESENT TWEEDLIKE PRECURSORS AND PARAELECTRIC CLUSTERS IN FERROELECTRICS CONTAINING STRONG QUENCHED RANDOMNESS

Transmission electron microscopy studies of the (1 - x)Pb(Mg1/3Nb2/3)O -3-(x)PbTiO3 [PMN-PT (1-x)/x] crystalline solution have been performed for x = 0.1, 0.2, 0.35, and 0.60. Bright-field imaging has revealed a common sequence of domainlike states with increasing x. Normal micron -sized ferroelectric domains were found for x>0.40. Tweedlike structur es were found for x similar to 0.35. These tweedlike structures are si milar to those previously reported in premartensitic states. Paraelect ric clusters were found for x<0.30. The paraelectric cluster state was characterized by the lack of self-assembly amongst embryos and the pr esence of relaxer behavior in the macroscopic response characteristics . The composition PMN-PT 65/35 was then modified with La for a detaile d study of the transition between the tweedlike precursor and paraelec tric cluster states with increasing impurity content. (C) 1995 America n Institute of Physics.