Observation of a time-dependent structural phase transition in potassium sodium bismuth titanate

High-energy synchrotron diffraction has been employed to demonstrate a time-dependent structural phase transition in 0.2K(1/2)Bi(1/2)TiO(3)-0.8Na(1/2)Bi(1/2)TiO(3). It is demonstrated that the rapid increase in electric field (>= 0.25 kV mm(-1) s(-1)) induces a transformation from rhombohedral to mixed phase rhombohedral and tetragonal symmetry. When the electric field is applied slowly (< 0.25 kV mm(-1) s(-1)), no transformation occurs, and rhombohedral symmetry is maintained. The extent of transformation increases with the rate of increase in electric field. High-speed capture of diffraction images (7 frames per second) has been used to show the evolution of the phase transformation as a function of time. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3582616]