Domain-like organizations in ferroelectrics containing quenched randomness

Abstract

Transmission electron microscopy studies of the (1-x)Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-(x)PbTiO/sub 3/ (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 domain-like states with increasing x. Normal micron-sized ferroelectric domains were found for x>0.40. Tweed-like structures were found for x/spl sim/0.35. These tweedlike structures are similar to those previously reported in pre-martensitic states. Paraelectric clusters were found for x<0.30. The paraelectric cluster state was characterized by the lack of self-assembly amongst embryos and the presence of relaxor behavior in the macroscopic response characteristics. The composition PMN-PT 65/35 was then modified with La for a detailed study of the transition between the tweed-like precursor and paraelectric cluster states with increasing impurity content.