Capacitance of thin Ferroelectric films obtained with different methods

Thin film Ferroelectric capacitance can be obtained with two methods. Capacitance obtained by the derivative of its hysteresis loop is related to large applied signal. Capacitance measured directly with small applied alternate current signal together with slow changing dc bias is related to small signal circuit analysis. This paper investigated the relationship between the two types of capacitance. Measurements show that C-V curves obtained with the first method have much sharper peaks and higher peak values. A model, which divides the polarization of Pb (Zr, Ti) O3 (PZT) into linear polarization and switching polarization, was utilized to analyze the mechanism.