A Janus CrSSe monolayer with interesting ferromagnetism

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Developing 2D ferromagnetic materials with high Curie temperature (T_C), magnetic anisotropy energy (MAE), and multiferroic coupling is crucial for next-generation spintronics.
• Intrinsic half-metallic ferromagnets are highly sought after for their potential in ultra-compact spintronic devices.

Purpose of the Study:

• To identify novel, stable 2D ferromagnetic Janus monolayers with desirable spintronic properties.
• To investigate the magnetoelectric and ferroelastic characteristics of newly discovered materials.
• To explore multiferroic coupling in 2D materials for advanced applications.

Main Methods:

• First-principles structural search calculations were employed to identify candidate materials.
• Density Functional Theory (DFT) was used to analyze magnetic, electronic, and mechanical properties.
• Calculations assessed Curie temperature (T_C), magnetic anisotropy energy (MAE), half-metallicity, and ferroelasticity.

Main Results:

• A stable ferromagnetic Janus monolayer, tetrahedral CrSSe, was identified with a high T_C of 790 K and MAE of 0.622 meV/Cr.
• The CrSSe monolayer exhibits robust half-metallicity and significant ferroelasticity with a modest energy barrier.
• Multiferroic coupling between in-plane magnetization and ferroelasticity was observed.
• Two new half-metallic ferromagnetic monolayers, CrS₂ and CrSe₂, were synthesized by atom substitution, also showing excellent magnetoelectric properties.

Conclusions:

• The discovery of CrSSe and related monolayers offers a promising route for designing novel multiferroic materials.
• These findings contribute to a deeper understanding of 2D transition metal chalcogenides and their spintronic potential.
• The identified materials are suitable for developing ultra-compact spintronic devices with enhanced functionalities.