Transition metal doping for tailoring magnetic properties of graphdiyne

Abstract

Tailoring the magnetic properties of semiconductors is crucial for realizing spintronic devices with integrated logic and memory functions. Graphdiyne (GDY), a two-dimensional carbon semiconductor, has emerged as a promising material for this purpose. This work demonstrates an effective approach to induce robust room-temperature ferromagnetism in GDY through in-situ transition metal (Fe, Co, Ni) doping via an improved liquid-liquid interface synthesis method. Density functional theory calculations reveal that the ferromagnetism originates from the Kagome lattice formed by the doped transition metal atoms. Remarkably, Fe-doped GDY exhibits a saturation magnetization of 2.86 emu · g−1 at room temperature, substantially higher than Co- and Ni-doped counterparts. Furthermore, post synthesis annealing treatment allows modulating the magnetic properties by introducing hydroxyl groups, with Co-GDY annealed at 500°C showing optimal room-temperature ferromagnetic behavior (0.26 emu · g−1). This work paves the way for tailoring magnetic semiconductors for spintronic applications by leveraging transition metal doping and defect engineering in graphdiyne.