Steplike Switching in Symmetric PbZr0.2Ti0.8O3/CoFeO4/PbZr0.2Ti0.8O3 Heterostructures for Multistate Ferroelectric Memory

Steplike Switching in Symmetric PbZr0.2Ti0.8O3/CoFeO4/PbZr0.2Ti0.8O3 Heterostructures for Multistate Ferroelectric Memory

Publication Type:

Journal Article

Source:

Physical Review Applied, Volume 8, Issue 3 (2017)

ISBN:

2331-7019

Abstract:

<p>A hysteresis loop with three polarization states is obtained in the case of a symmetric epitaxial ferroelectric-interlayer-ferroelectric structure with bottom and top SrRuO3 electrodes. The ferroelectric layers are of PbZr0.2Ti0.8O3, while the interlayer is CoFe2O4. It is shown that the three polarization states can be separately accessed, suggesting that this type of structure can be used as building element for a three-state nonvolatile ferroelectric random-access memory (FERAM). The presence of the three-state memory effect is explained through a simple phenomenological model based on Landau-Ginzburg-Devonshire theory. The findings of this study can pave the way to multistate all-oxide FERAM devices, resulting in a 50% increase in the storage density compared to actual nonvolatile memories.</p>