# Tri-layer superlattices: A route to magnetoelectric multiferroics?

## TL;DR

This study computationally investigates tri-layer superlattices as a potential pathway to create magnetoelectric multiferroics, highlighting the limited polarization contribution from tri-layering but emphasizing strain-induced polarization enhancement.

## Contribution

It demonstrates that strain and negative pressure can induce large, switchable polarizations in superlattices without active ferroelectric ions, offering a new approach to multiferroic design.

## Key findings

- Tri-layering contributes minimally to polarization.
- Epitaxial strain and negative pressure induce large switchable polarization.
- Magnetism can coexist with strain-induced polarization in these structures.

## Abstract

We explore computationally the formation of tri-layer superlattices as an alternative approach for combining ferroelectricity with magnetism to form magnetoelectric multiferroics. We find that the contribution to the superlattice polarization from tri-layering is small compared to typical polarizations in conventionalferroelectrics, and the switchable ferroelectric component is negligible. In contrast, we show that epitaxial strain and ``negative pressure'' can yield large, switchable polarizations that are compatible with the coexistence of magnetism, even in materials with no active ferroelectric ions.