Distorted Monolayer ReS₂ with Low-Magnetic-Field Controlled Magnetoelectricity

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials with ferroelectric and ferromagnetic orders are crucial for spintronics and multistate data storage.
• Realizing ferroelectric and magnetoelectric (ME) dipoles in atom-thick 2D materials is challenging due to structural inversion symmetry, thermal effects, and depolarized fields.

Purpose of the Study:

• To overcome limitations in creating 2D ferroelectric and magnetoelectric materials.
• To engineer 2D materials with in-plane inversion asymmetry for out-of-plane ferroelectric polarization.
• To achieve low-magnetic-field controlled magnetoelectricity in 2D materials.

Main Methods:

• Utilized crystal chemistry to induce specific atomic displacements in monolayer ReS₂.
• Modified crystal symmetry to achieve room-temperature out-of-plane ferroelectric polarization.
• Introduced cationic Re vacancies to create spin polarization and magnetic ordering.

Main Results:

• Successfully engineered monolayer ReS₂ with out-of-plane ferroelectric polarization at room temperature.
• Demonstrated that Re vacancies induce spin polarization and magnetic ordering in ReS₂.
• Achieved low-magnetic-field controlled ME coupling multiferroics at approximately 28 K.

Conclusions:

• Developed a design methodology for coexisting ferroelectric and ferromagnetic orders in 2D materials.
• Provided new insights into the mechanisms of magnetoelectricity in 2D materials.
• Achieved 2D ME coupling multiferroics with potential for spintronics and data storage.