Critical properties of symmetric nanoscale metal-ferroelectric-metal capacitors

摘要

The size, surface and interface effects on the magnitude and stability of spontaneous polarization in a symmetric nanoscale ferroe trie capacitor were studied by analyzing its evolutionary trajectory based on a thermodynamic model. Analytic expressions of the C temperature, spontaneous polarization, critical thickness and the Curie-Weiss relation were derived, taking into account the effects of depolarization field, built-in electric field, interfaces and surfaces. Our results show that the critical properties are not only function the ambient temperature, misfit strain and electromechanical boundary conditions, but also depend on the characteristics of electroi surfaces and interfaces, through the incomplete charge compensation, near-surface variation of polarization and work function step ferroelectric-electrode interfaces, which are adjustable.