Observability of negative capacitance of a ferroelectric film: Theoretical predictions

We theoretically explore mechanisms that can potentially give rise to the steady-state and transient negative capacitance in a uniaxial ferroelectric film stabilized by dielectric layer. The analytical expressions for of single-domain polydomain states are derived within Landau-Ginzburg-Devonshire approach used study state stability vs domain splitting as function layer thickness. Analytical critical thickness layer, polarization amplitude, equilibrium period, susceptibility obtained corroborated finite element modeling. further possible effects nonlinear screening two types charges at ferroelectric-dielectric interface show if least one is very slow, total dynamics exhibit complex time- voltage-dependent behaviors be interpreted an observable capacitance. In this setting, effect accompanied almost zero wide voltage range low frequencies. These results may help elucidate observation thin films, identify materials systems behavior.