Intrinsic ferromagnetism and restrictive thermodynamic stability in MA$$_{2}$$N$$_{4}$$ and Janus VSiGeN$$_{4}$$ monolayers

Journal Article · Mon Jun 27 00:00:00 UTC 2022 · Physical Review Materials

DOI: https://doi.org/10.1103/PhysRevMaterials.6.L061002 · OSTI ID:1873975

Dey, Dibyendu ^[1]; Ray, Avijeet ^[2]; Yu, Liping ^[3]

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1. Univ. of Maine, Orono, ME (United States); university of maine, orono
2. Indian Inst. of Technology Roorkee, Uttarakhand (India)
3. Univ. of Maine, Orono, ME (United States)

The seminal experimental discovery of the remarkably stable MoSi₂N₄ monolayer has led to a handful of predicted magnetic two-dimensional (2D) materials in the MA₂Z₄ family (M = transition metals, A = Si, Ge, and Z = N, P, As). These magnetic monolayers were predicted to be dynamically stable, but none of them has been synthesized to date. In this Research Letter, from first-principles thermodynamic stability analysis, we demonstrate that only the nitrides are thermodynamically stable and this occurs under N-rich conditions. Based on this finding, we propose two ferromagnetic, semiconducting Janus monolayers in the family: VSiGeN₄ and VSiSnN₄. They are both dynamically and thermally stable, but only the former is thermodynamically stable. Intriguingly, Janus VSiGeN₄ and VSiSnN₄ monolayers show weak in-plane anisotropy compared with the VSi₂N₄ monolayer. Furthermore, these two emerging Janus magnetic semiconductors offer opportunities for studying 2D magnetism and spin control for spintronics applications.

• Research Organization: Univ. of Maine, Orono, ME (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0021127
• OSTI ID: 1873975
• Journal Information: Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 6 Vol. 6; ISSN 2475-9953
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English