Tunnel electroresistance in junctions with ultrathin ferroelectric Pb(Zr0.2Ti0.8)O3 barriers

Authors

Daniel Pantel, Max Planck Institute of Microstructure Physics
Haidong Lu, University of Nebraska-LincolnFollow
Silvana Goetze, Max Planck Institute of Microstructure Physics
Peter Werner, Max Planck Institute of Microstructure PhysicsFollow
Dong Jik Kim, University of Nebraska-LincolnFollow
Alexei Gruverman, University of Nebraska-LincolnFollow
Dietrich Hesse, Max Planck Institute of Microstructure Physics
Marin Alexe, Max Planck Institute of Microstructure PhysicsFollow

Date of this Version

2012

Citation

APPLIED PHYSICS LETTERS 100, 232902 (2012); http://dx.doi.org/10.1063/1.4726120

Comments

Copyright 2012 American Institute of Physics. Used by permission.

Abstract

In ferroelectric tunnel junctions, the ferroelectric polarization state of the barrier influences the quantum-mechanical tunneling through the junction, resulting in tunnel electroresistance (TER). Here, we investigate tunnel electroresistance in Co/PbZr_0.2Ti_0.8O₃/La_0.7Sr_0.3MnO₃ tunnel junctions. The ferroelectric polarization in tunnel junctions with 1.2-1.6 nm (three to four unit cells) PbZr_0.2Ti_0.8O₃ thickness and an area of 0.04 μm² can be switched by about 1 V yielding a resistive ON/OFF-ratio of about 300 at 0.4 V. Combined piezoresponse force microscopy and electronic transport investigations of these junctions reveal that the transport mechanism is quantum tunneling and the resistive switching in these junctions is due only to ferroelectric switching.