Prediction of Two-Dimensional Janus Transition-Metal Chalcogenides: Robust Ferromagnetic Semiconductor with High...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Quantum Information Technology

Background:

• Two-dimensional (2D) ferromagnetic semiconductors (FM SCs) are crucial for nanoscale spintronic devices.
• Existing 2D FM materials often suffer from low Curie temperatures (T_C), hindering practical applications.

Purpose of the Study:

• To predict and investigate novel 2D FM SCs with enhanced properties.
• To explore the magnetic and electronic characteristics of V₃Se₃X₂ (X = S, Te) monolayers.

Main Methods:

• First-principles calculations were employed to predict material properties.
• Phonon dispersion and ab initio molecular dynamics (AIMD) were used to assess stability.

Main Results:

• V₃Se₃Te₂ and V₃Se₃S₂ monolayers exhibit moderate (0.53 eV) and direct (0.59 eV) bandgaps, respectively.
• Both materials display robust ferromagnetism with high T_Cs of 406 K (V₃Se₃S₂) and 301 K (V₃Se₃Te₂).
• A transition to antiferromagnetic (AFM) states was observed under biaxial tensile strain (3-5%).

Conclusions:

• V₃Se₃S₂ and V₃Se₃Te₂ monolayers are stable 2D FM SCs with promising properties for spintronics.
• Their high T_Cs, tunable magnetic phases, and mechanical/thermal stability make them suitable for quantum information technology.