Room Temperature Nanoscale Ferroelectricity in Magnetoelectric GaFeO3 Epitaxial Thin Films

TL;DR

This study demonstrates room temperature nanoscale ferroelectricity in epitaxial GaFeO3 thin films, revealing a magneto-dielectric effect and identifying Fe ions as key to its multiferroic properties.

Contribution

It provides the first evidence of room temperature ferroelectricity in epitaxial GaFeO3 films and links Fe ions to both magnetic and ferroelectric behaviors.

Findings

Nanoscale ferroelectricity observed at room temperature

Pronounced magneto-dielectric effect across magnetic transition

Fe ions responsible for both ferrimagnetism and ferroelectricity

Abstract

We demonstrate room temperature ferroelectricity in the epitaxial thin films of magnetoelectric GaFeO3. Piezo-force measurements show a 180o phase shift of piezoresponse upon switching the electric field indicating nanoscale ferroelectricity in epitaxial thin films of gallium ferrite. Further, temperature dependent impedance analysis with and without the presence of an external magnetic field clearly reveals a pronounced magneto-dielectric effect across the magnetic transition temperature. In addition, our first principles calculations show that Fe ions are not only responsible for ferrimagnetism as observed earlier, but also give rise to the observed ferroelectricity, making GFO an unique single phase multiferroic.