Optimized Voltage-Induced Control of Magnetic Domain-Wall Propagation in Hybrid Piezoelectric/Magnetostrictive Devices

Giancarlo Consolo,Giovanna Valenti

doi:10.3390/act10060134

Abstract

A theory of voltage-induced control of magnetic domain walls propagating along the major axis of a magnetostrictive nanostrip, tightly coupled with a ceramic piezoelectric, is developed in the framework of the Landau–Lifshitz–Gilbert equation. It is assumed that the strains undergone by the piezoelectric actuator, subject to an electric field generated by a dc bias voltage applied through a couple of lateral electrodes, are fully transferred to the magnetostrictive layer. Taking into account these piezo-induced strains and considering a magnetostrictive linear elastic material belonging to the cubic crystal class, the magnetoelastic field is analytically determined. Therefore, by using the classical traveling-wave formalism, the explicit expressions of the most important features characterizing the two dynamical regimes of domain-wall propagation have been deduced, and their dependence on the electric field strength has been highlighted. Moreover, some strategies to optimize such a voltage-induced control, based on the choice of the ceramic piezoelectric material and the orientation of dielectric poling and electric field with respect to the reference axes, have been proposed.

Highlights

Domain walls (DWs) in ferromagnetic nanostripes have been receiving great attention by researchers both from the theoretical viewpoint [1,2,3] and for their potential applications in DW-based devices, such as memories, logic gates and sensors [4,5,6,7,8]
We develop the theoretical framework used to describe the propagation of magnetic DWs along the major axis of a thin MS nanostrip placed in tight contact with a PZ actuator
Our theoretical results demonstrated that the propagation of DWs along the major axis of a MS nanostrip, placed on the top of a thick PZ actuator, can be controlled by the electric field generated into the PZ layer via a dc bias voltage

Summary

Introduction

Domain walls (DWs) in ferromagnetic nanostripes have been receiving great attention by researchers both from the theoretical viewpoint [1,2,3] and for their potential applications in DW-based devices, such as memories, logic gates and sensors [4,5,6,7,8]. In these contexts, achieving an effective control of the DW features by means of several external sources, such as magnetic fields, spin-polarized currents and/or electrically-induced mechanical strains, becomes fundamental.

Methods

Results

Conclusion