Electrical Writing of Magnetic and Resistive Multistates in CoFe Films Deposited onto Pb[Zr$_x$Ti$_{1-x}$]O$_3$

TL;DR

This paper demonstrates electric writing of multistate magnetic and resistive states in CoFe films on piezoelectric Pb[Zr$_x$Ti$_{1-x}$]O$_3$, enabling low-energy multistate memory functionalities with optimized film thickness.

Contribution

It introduces a multistate memory device combining resistive and magnetoresistive functionalities using strain-mediated coupling in CoFe/Pb[Zr$_x$Ti$_{1-x}$]O$_3$ systems, extending reversible bistable control.

Findings

Optimal CoFe thickness around 100 nm for best coupling.

Achieved multistate memory with resistive and magnetoresistive states.

Demonstrated low-energy multistate memory device.

Abstract

Electric control of magnetic properties is an important challenge for modern magnetism and spintronic development. In particular, an ability to write magnetic state electrically would be highly beneficial. Among other methods, the use of electric field induced deformation of piezoelectric elements is a promising low-energy approach for magnetization control. We investigate the system of piezoelectric substrate Pb[Zr$_x$Ti$_{1-x}$]O$_3$ with CoFe overlayers, extending the known reversible bistable electro-magnetic coupling to surface and multistate operations, adding the initial state reset possibility. Increasing the CoFe thickness improves the magnetoresistive sensitivity, but at the expenses of decreasing the strain-mediated coupling, with optimum magnetic thin film thickness of the order of 100 nm. The simplest resistance strain gauge structure is realized and discussed as a multistate memory cell demonstrating both resistive memory (RRAM) and magnetoresistive memory (MRAM) functionalities in a single structure.