Optical spectroscopic investigation on the coupling of electronic and magnetic structure in multiferroic hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films

TL;DR

This study uses optical spectroscopy to explore how temperature and magnetic fields influence the electronic and magnetic coupling in hexagonal RMnO3 thin films, revealing significant shifts in electronic structure linked to magnetic ordering.

Contribution

It provides new insights into the coupling between magnetic and electronic structures in multiferroic hexagonal RMnO3 thin films through systematic optical spectroscopy analysis.

Findings

Large shift (>150 meV) in optical absorption peak near 1.7 eV with temperature change.

Anomaly in peak shift observed at the Neel temperature.

Magnetic field induces a sizable shift in the electronic structure.

Abstract

We investigated the effects of temperature and magnetic field on the electronic structure of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films using optical spectroscopy. As the magnetic ordering of the system was disturbed, a systematic change in the electronic structure was commonly identified in this series. The optical absorption peak near 1.7 eV showed an unexpectedly large shift of more than 150 meV from 300 K to 15 K, accompanied by an anomaly of the shift at the Neel temperature. The magnetic field dependent measurement clearly revealed a sizable shift of the corresponding peak when a high magnetic field was applied. Our findings indicated strong coupling between the magnetic ordering and the electronic structure in the multiferroic hexagonal RMnO3 compounds.