A Schottky contact consisting of a semiconducting ferroelectric materi
al and a high work function metal shows a bistable conduction characte
ristic. An on/off ratio of about 2 orders of magnitude was obtained in
a structure consisting of a 0.2 mu m ferroelectric PbTiO3 film, a Au
Schottky contact, and a La0.5Sr0.5CoO3 Ohmic bottom electrode. The obs
ervations are explained by a model in which the depletion width of the
ferroelectric Schottky diode is determined by the polarization depend
ence of the internal electric field at the metal-ferroelectric interfa
ce.