Large Longitudinal Magnetoelectric Coupling in NiFe2O4-BaTiO3 Laminates

TL;DR

This study demonstrates significant longitudinal magnetoelectric coupling in NiFe2O4-BaTiO3 laminates, with enhanced effects achieved by reducing layer thickness and increasing layer number, offering environmentally friendly alternatives to Pb-based devices.

Contribution

It reveals large longitudinal ME coupling in NiFe2O4-BaTiO3 laminates and shows how to optimize ME effects through layer thickness and stacking, advancing Pb-free magnetoelectric materials.

Findings

Longitudinal ME voltage coefficient Alpha E33 exceeds transverse in these laminates.

Reducing layer thickness to 15 um enhances Alpha E33 up to 18 mV/(cm Oe).

ME sensitivity increases with the number of layers, reaching 400*10^-6 V/Oe.

Abstract

In contrast to the Pb-based magnetoelectric laminates (MELs), we find in the BaTiO3 and NiFe2O4 laminates (number of layers n = 5-25) that the longitudinal magnetoelectric (ME) voltage coefficient Alpha E33 becomes much larger than the transverse one due to preferential alignment of magnetic moments along the NiFe2O4 plane. Moreover, upon decreasing each layer thickness down to 15 um, we realize enhanced Alpha E33 up to 18 mV/ (cm Oe) and systematic increase of the ME sensitivity in proportion to n to achieve the largest in the Pb-free MELs (400*10^-6V/Oe), thereby providing pathways for tailoring ME coupling in mass-produced, environment friendly laminates.