Ferroelectric nanodomains in the uniaxial relaxor system Sr0.61-xBa0.39Nb2O6 : Ce-x(3+)

Abstract

The domain morphology of the disordered relaxor ferroelectric strontium barium niobate doped with cerium, Sr0.61-xBa0.39Nb2O6Cex3+, has been investigated by piezoelectric force microscopy. The evolution of natural and written domains above the phase-transition temperature T-c reveals a very slow relaxation into a depolarized multicluster state. This hints at strong pinning forces due to quenched random fields. Below T-c zero-field-cooled nanodomains are observed to show fractal-like shapes. Their size distribution can be described by a power law with exponential cutoff in accordance with the random-field Ising model.