Ferroelectrics · 2008 · 43 citations · 23 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsMaterials PhysicsSolid State PhysicsDielectric CeramicsDielectric PropertiesDielectricsElectrical Properties Of CeramicsFerroelectric MaterialsPhase TransitionsDielectric FunctionFerroelectric CrystalsFerroelectric Domain FormationFerroelectric PropertiesFerroelectric RelaxationFerroelectric Single CrystalsFerroelectricityRelaxor Ferroelectrics
The crossover of single crystalline Sr x Ba 1 − x Nb 2 O 6 (SBN) from ferroelectric to relaxor behavior when increasing the Sr 2+ content from x = 0.4 to x = 0.75 is investigated by dielectric low-frequency susceptometry and scanning piezo-force microscopy. Increasing quenched random electric fields are conjectured to be responsible for the observed increasing dielectric polydispersivity and the growing fractality of the polar 180° domains. A simple statistical model taking into account the varying occupation of the different A-sites with vacancies, Sr 2+ and Ba 2+ ions, and their influence on the average RF strength is proposed to describe the transformation to the relaxor behavior with increasing x.
23