Large magnetic anisotropy in Tetraoxa[8]circulene-based organometallic nanosheet

Exploring magnetic anisotropy (MA) in single-atom-doped two-dimensional (2D) materials is greatly needed for the development of nanomagnetic devices. Taking full advantage of the natural hollow sites of 2D Tetraoxa[8]circulene-based nanosheet (TOC), we systemically study the MA of the TOC doped by single 3d tradition metal (TM) atoms (V, Cr, Mn, Fe, Co and Ni) via first-principles calculations. Specifically, we find that the Co@TOC system has large perpendicular magnetic anisotropy (PMA), up to 1.76 meV/atom, which originates from the hybridization of Co-(d_xz, d_yz) and O-p_z orbitals with strong spin-orbit splitting near Fermi level. Furthermore, the PMA of Co@TOC can be enhanced up to 7.28 meV/atom by applying biaxial tensile strain of 9%. The large PMA provides a practical single-atom magnetic system for potential spintronic applications.