Room-temperature two-dimensional multiferroic metal with voltage-controllable magnetic order

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Achieving room-temperature two-dimensional multiferroics with strong magnetoelectric coupling is challenging due to conflicting ferroelectric and magnetic properties.
• Existing methods often rely on spin-orbit coupling, limiting material design.
• Robust electric-field control of magnetism at ambient temperatures is crucial for next-generation electronics.

Purpose of the Study:

• To report a novel two-dimensional multiferroic material with intrinsic room-temperature multiferroicity.
• To demonstrate electric-field control of magnetism in a layered system.
• To explore a new mechanism for multiferroicity based on interlayer charge transfer.

Main Methods:

• Synthesis and characterization of air-stable bilayer CrTe₂.
• Structural and magnetic analysis to determine bilayer architecture.
• Scanning probe microscopy to confirm electric-field control of magnetization.

Main Results:

• Discovery of intrinsic room-temperature multiferroicity in bilayer CrTe₂.
• Identification of an alternating ferromagnetic/antiferromagnetic bilayer structure driven by interlayer charge transfer.
• Demonstration of switchable ferroelectric polarization and non-volatile electric-field control of magnetization states.
• Confirmation of electrical writing and magnetic reading functionalities.

Conclusions:

• Bilayer CrTe₂ is a stable, two-dimensional multiferroic material with room-temperature magnetoelectric coupling.
• Interlayer charge transfer, not spin-orbit coupling, is the key mechanism, offering a new design principle for layered multiferroics.
• This material enables energy-efficient memory devices and advanced quantum sensing technologies.