title: Intrinsic half-metallicity in fractal carbon nitride honeycomb lattices.
abstract: Fractals are natural phenomena that exhibit a repeating pattern "exactly the same at every scale or nearly the same at different scales". Defect-free molecular fractals were assembled successfully in a recent work [Shang et al., Nature Chem., 2015, 7, 389-393]. Here, we adopted the feature of a repeating pattern in searching two-dimensional (2D) materials with intrinsic half-metallicity and high stability that are desirable for spintronics applications. Using first-principles calculations, we demonstrate that the electronic properties of fractal frameworks of carbon nitrides have stable ferromagnetism accompanied by half-metallicity, which are highly dependent on the fractal structure. The ferromagnetism increases gradually with the increase of fractal order. The Curie temperature of these metal-free systems estimated from Monte Carlo simulations is considerably higher than room temperature. The stable ferromagnetism, intrinsic half-metallicity, and fractal characteristics of spin distribution in the carbon nitride frameworks open an avenue for the design of metal-free magnetic materials with exotic properties.
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China. zmw@sdu.edu.cn.
authors.forename: Aizhu
authors.initials: A
authors.lastname: Wang
authors.forename: Mingwen
authors.initials: M
authors.lastname: Zhao
mesh_terms: D004583:Electrons; D017709:Fractals; D060328:Magnetic Phenomena; D008958:Models, Molecular; D008968:Molecular Conformation; D009010:Monte Carlo Method; D009570:Nitriles / Q000737:chemistry*; D011789:Quantum Theory; D013696:Temperature
chemical_list: D009570:Nitriles; C011206:cyanogen