A single ferroelectric Schottky diode was obtained on a ${\text{SrRuO}}_3\text{-Pb}\left({\text{Zr}}_{0.2}{\text{Ti}}_{0.8}\right){\text{O}}_3\text{-Ta}$ (SRO-PZT20/80-Ta) structure in which the SRO-PZT20/80 interface is the rectifying contact and the PZT20/80-Ta interface behaves as a quasiohmic contact. Both the capacitance-voltage $\left(C\text{−}V\right)$ and the current-voltage $\left(I\text{−}V\right)$ characteristics show the memory effect due to the ferroelectric polarization. However, retention studies had revealed that only the “down” orientation of ferroelectric polarization is stable in time (polarization oriented from top to bottom contact). The analysis of the experimental results suggests that the PZT20/80 is $n$ type and that the stable orientation of polarization is related to the presence of a depletion region at the SRO-PZT20/80 Schottky interface.

• Received 12 February 2010

DOI:https://doi.org/10.1103/PhysRevB.82.085319