Topologically Frustrated Graphene Antidot Lattice Semiconductors with Room-Temperature Magnetism

Realizing graphene spintronics is intriguing due to the weak spin–orbital coupling; however, developing intrinsic room-temperature magnetic semiconductors in graphene is still a great challenge. Graphene antidot lattices (GALs), as a type of regular vacancy graphene, exhibit topology-dependent magnetism and offer an ideal platform to achieve room-temperature magnetic semiconductors. Recently, on-surface-synthesized open-shell [n]triangulene polymers as topologically frustrated graphene nanoflakes (GNFs) are the new building blocks to construct topologically frustrated GALs with robust magnetism. Herein, on the basis of the density functional theory calculations, we report seven magnetic GAL semiconductors by assembling two types of open-shell GNFs with topological frustration, that is, isomeric π-extended heptauthrene (cis triangulene dimer) and heptazethrene (trans triangulene dimer). Our results demonstrate that topologically frustrated GALs are semiconductors with either bipolar ferromagnetism or antiferromagnetism, inheriting the topologically frustrated magnetism from their building blocks. In particular, three ferromagnetic and two antiferromagnetic GALs exhibit above room-temperature magnetic order with their Curie or Néel temperatures varying from 507 to 527 or 366 to 391 K, respectively. This study provides a feasible route to obtain topologically frustrated GAL semiconductors with the above room-temperature magnetism from open-shell GNFs for graphene spintronics applications.