Co ₃ X ₈ (X = Cl and Br): multiple phases and magnetic properties of the Kagome lattice

The unique magnetic properties of two-dimensional (2D) materials have demonstrated huge potential for applications in nanodevices and spintronics. In this work, we propose a new Kagome lattice, Co₃X₈ (X = Cl and Br), based on density functional theory (DFT) calculation. We find that Co/X in Co₃X₈ has spontaneous movement in the lattice, resulting in 156- and 12-phases of Co₃X₈ and diverse magnetic and electronic properties. We show that the magnetic and electronic properties of Co₃X₈ can be engineered by strain, and the magnetic properties of Co₃X₈ are highly related to the spontaneous movement of X. Moreover, the transmission property of 12-Co₃X₈ shows clear angle-dependent features due to the symmetry breaking as caused by the spontaneous movement of X. Our findings may provide not only a possible Kagome lattice with unique properties, but also a strategy for designing nanodevices and for spintronics.