Proximity-Mediated Multi-Ferroelectric Coupling in Highly Strained EuO-Graphene Heterostructures

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• 2D van der Waals materials and heterostructures are key for exploring quantum hybridization effects.
• The magnetic proximity effect in spintronics utilizes spin-dependent hybridization.
• Previous theoretical work predicted strain-induced ferroelectricity in Europium Oxide (EuO).

Purpose of the Study:

• To investigate the proximity-controlled magnetoelectric effect in EuO/graphene heterostructures.
• To create a novel multiferroic hybrid heterostructure with multifunctional properties.
• To confirm theoretical predictions of strain-induced ferroelectricity in EuO.

Main Methods:

• Growth of magnetic insulating EuO thin films on graphene using a topotactic method.
• Application of high compressive strain to the EuO/graphene heterostructure.
• Characterization of magnetoelectric and ferroelectric properties at room temperature.

Main Results:

• A new multiferroic hybrid heterostructure (EuO/graphene) was successfully created.
• High compressive strain induced ferroelectric order in EuO, reaching 18 µC cm⁻² polarization at room temperature.
• EuO induced a magnetic proximity state in the graphene layer via interfacial hybridization.
• Coexistence of ferroelectric and magnetic states in the heterostructure up to room temperature.

Conclusions:

• The study demonstrates a proximity-controlled magnetoelectric effect in strained EuO/graphene heterostructures.
• The observed phenomena confirm long-standing theoretical predictions of strain-induced ferroelectricity in EuO.
• These findings highlight the potential for manipulating magnetization and electric polarization in future memory and neuromorphic devices.