“…In addition, the field dependent dielectric constant of BTO/Pt/Ti/Si shows a good symmetry, while an obvious asymmetry is found for BTO/LNO/Si. The asymmetry of the field dependent dielectric constant is a common phenomenon that had been repeatedly observed in many ferroelectric thin films, which may be attributed to the asymmetry structure of the top and bottom electrodes and the interface effects between the bottom electrodes and the ferroelectric films [26,27].…”