Tailoring graphene magnetism by zigzag triangular holes: A first-principles thermodynamics study

We discuss the thermodynamic stability and magnetic property of zigzag triangular holes (ZTHs) in graphene based on the results of first-principles density functional theory calculations. We find that ZTHs with hydrogen-passivated edges in mixed sp²/sp³ configurations (z₂₁₁) could be readily available at experimental thermodynamic conditions, but ZTHs with 100% sp² hydrogen-passivation (z₁) could be limitedly available at high temperature and ultra-high vacuum conditions. Graphene magnetization near the ZTHs strongly depends on the type and the size of the triangles. While metallic z₁ ZTHs exhibit characteristic edge magnetism due to the same-sublattice engineering, semiconducting z₂₁₁ ZTHs do show characteristic corner magnetism when the size is small <2 nm. Our findings could be useful for experimentally tailoring metal-free carbon magnetism by simply fabricating triangular holes in graphene.