Two-dimensional ferromagnetic semiconductor Cr₂XP: first-principles calculations and Monte Carlo simulations

Area of Science:

• Materials Science
• Condensed Matter Physics
• Quantum Chemistry

Background:

• Two-dimensional (2D) intrinsic ferromagnetic semiconductors are crucial for spintronic devices.
• The Mermin-Wagner theorem poses challenges for achieving room-temperature Curie temperatures in 2D materials.

Purpose of the Study:

• To design novel 2D intrinsic ferromagnetic semiconductors with room-temperature ferromagnetism.
• To investigate the electronic and magnetic properties of the Cr2XP (X = P, As, Sb) material system.

Main Methods:

• Band engineering approach for material design.
• First-principles calculations to analyze electronic structure and bonding.
• Monte Carlo simulations based on the Heisenberg model for Curie temperature estimation.
• Magnetic second-order perturbation theory for magnetic anisotropy energy analysis.

Main Results:

• Successfully designed Cr2XP (X = P, As, Sb) as a promising 2D room-temperature ferromagnetic semiconductor.
• Calculated large magnetic moments (6.16-6.37 μB) due to Cr-d electron occupation.
• Estimated high Curie temperatures (up to 1590 K for Cr2SbP).
• Demonstrated excellent thermodynamic, dynamical, thermal, and mechanical stability, enabling freestanding 2D structures.

Conclusions:

• Cr2XP materials offer a viable platform for next-generation spintronic devices.
• The designed materials overcome theoretical limitations for room-temperature ferromagnetism in 2D systems.
• These findings provide valuable insights for the development of advanced 2D magnetic semiconductors.