# Electric‐Field Control of Low Damping Constant in Epitaxial Co2FeSi/LiNbO3 Multiferroic Heterostructures

## TL;DR

This paper shows how an electric field can control magnetization in a special material, leading to energy-efficient magnonic devices.

## Contribution

The study demonstrates electric-field modulation of magnetization dynamics in an epitaxial Co2FeSi/LiNbO3 heterostructure with low damping.

## Key findings

- The heterostructure has a low damping constant of ∼0.006.
- Applying an electric field reduces the damping constant to ∼0.004.
- Piezoelectric strain from LiNbO3 controls magnetization dynamics via magnetoelastic coupling.

## Abstract

To develop electric‐field control of magnetization dynamics in a magnetic material for magnonic devices with low‐energy power consumption operation, an epitaxial half‐metallic Co2FeSi/LiNbO3 multiferroic heterostructure is experimentally demonstrated. The epitaxial Co2FeSi/LiNbO3 multiferroic heterostructure shows a low damping constant (α) of ∼0.006 and the value of α is decreased to ∼0.004 by applying an electric field. This means that the magnetization dynamics in an epitaxial half‐metallic Co2FeSi layer can be controlled via the piezoelectric strain of LiNbO3 through the magnetoelastic coupling. This study leads to a way toward the realization of magnonic devices with low‐energy power consumption operation.

The development of multiferroic heterostructures with a half‐metallic property is one of the key technologies for electric‐field operatable magnonic devices. In this study, Co2FeSi/LiNbO3 multiferroic heterostructures with a low damping constant are experimentally developed and an electric‐field modulation of its magnetization dynamics is demonstrated.