Robust ferromagnetism in two-dimensional GeC/CrN heterobilayers.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Exploring novel 2D materials for advanced electronic and magnetic applications.
• Heterobilayers offer tunable properties through material combinations and stacking.
• Germanium carbide (GeC) and chromium nitride (CrN) are promising candidates for spintronic devices.

Purpose of the Study:

• Investigate the electronic and magnetic properties of GeC/CrN heterobilayers.
• Determine the impact of stacking, twist angles, and biaxial strain on material properties.
• Assess the potential of GeC/CrN heterobilayers for spintronic applications.

Main Methods:

• First-principles calculations using density functional theory (DFT) with Hubbard U correction.
• Effective anisotropic Heisenberg spin model for magnetic properties.
• Phonon spectra analysis for dynamical stability.
• Random Phase Approximation (RPA) for Curie temperature calculations.

Main Results:

• All stacking configurations exhibit half-metallicity and an out-of-plane ferromagnetic ground state.
• High Curie temperatures (Tc) were predicted for GeC/CrN heterobilayers.
• Half-metallicity is independent of stacking and twist angles.
• Biaxial strain significantly influences magnetic anisotropy energy and Curie temperature, with values remaining above room temperature.

Conclusions:

• GeC/CrN heterobilayers are dynamically stable and possess desirable half-metallic ferromagnetic properties.
• Strain engineering offers a pathway to tune magnetic anisotropy and Curie temperature.
• The combination of a wide band gap, commensurate lattice, and high Tc makes CrN on GeC a strong candidate for future spintronic devices.