Multistate nonvolatile straintronics controlled by a lateral electric field

TL;DR

This paper introduces a multistate nonvolatile memory device that uses lateral electric fields to control strain, enabling stable, rewritable resistance and magnetic state changes in a single device for advanced memory applications.

Contribution

It demonstrates a multifunctional memory device with 17 stable states, combining strain, magnetic, and resistive functionalities controlled by sub-coercive electric fields.

Findings

17 stable memory states demonstrated

Resistance and magnetic properties are rewritable and persistent

Device integrates strain, magnetic, and resistive functionalities

Abstract

We present a multifunctional and multistate permanent memory device based on lateral electric field control of a strained surface. Sub-coercive electrical writing of a remnant strain of a PZT substrate imprints stable and rewritable resistance changes on a CoFe overlayer. A proof-of-principle device, with the simplest resistance strain gage design, is shown as a memory cell exhibiting 17-memory states of high reproducibility and reliability for nonvolatile operations. Magnetoresistance of the film also depends on the cell state, and indicates a rewritable change of magnetic properties persisting in the remnant strain of the substrate. This makes it possible to combine strain, magnetic and resistive functionalities in a single memory element, and suggests that sub-coercive stress studies are of interest for straintronics applications.