Magnetoelectric coupling in epitaxial orthorhombic YMnO3 thin films

TL;DR

This study demonstrates substrate-induced strain effects on the magnetic and dielectric properties of epitaxial orthorhombic YMnO3 thin films, revealing magnetoelectric coupling and controllable magnetic structure through substrate choice.

Contribution

It provides the first evidence of magnetoelectric coupling in epitaxial orthorhombic YMnO3 thin films influenced by substrate strain.

Findings

Substrate-induced in-plane compression of YMnO3 unit cell.

Significant ZFC-FC hysteresis below TN (~40K).

Dielectric constant increases up to 26% below TN.

Abstract

We have grown epitaxial thin-films of the orthorhombic phase of YMnO3 oxide on Nb:SrTiO3(001) substrates and their structure, magnetic and dielectric response have been measured. We have found that a substrate-induced strain produces an in-plane compression of the YMnO3 unit cell. The temperature-dependent magnetization curves display a significant ZFC-FC hysteresis at temperatures below the Neel temperature (TN around 40K). The dielectric constant increases gradually (up to 26%) below TN and mimics the ZFC magnetization curve. We argue that these effects are a manifestation of magnetoelectric coupling in thin films and that the magnetic structure of YMnO3 can be controlled by substrate selection.