Current change due to artificial patterning of the number of ferroelectric domain walls and nonvolatile memory characteristics

Abstract

Domain walls (DWs) are formed at the boundaries between domains formed in a ferroelectric, and experimental results have been reported on the phenomenon of electrical conductivity in the DW. DW conduction nonvolatile memory applications are possible by forming and removing DWs with the high DW conductivity (DWC). Here, we investigated two-electrode devices and three-electrode DWC nonvolatile devices with current–voltage curves that change according to the number of DWs. When the number of DWs formed in the epitaxial PbTiO3 thin film was changed to 0, 2, and 4, the resistance of DWC was observed to decrease in the two-electrode device. For a three-electrode DWC nonvolatile memory having three electrodes with a structure similar to that of a flash memory structure, the slope of the source-drain current–voltage curve was adjusted by the gate electrode, and showed nonvolatile characteristics that can replace the flash memory.