Theoretical Design And Properties’Regulation Of Carbon Hybrid Magnetic Materials

The so called nanomaterials are those geometry size between lnm and100nm, and those nanomaterials own some novel characteristic because of the size effect and large surface effect, which has made great progress in physics, chemistry and material science. The applications of nanomaterials across various fields, including magnetic nano-materials, nano-semiconductor materials, nano-catalytic materials and so on.Unlike conventional magnetic,the special physical length associated with magnetic of magnetic nano-materials is in the order of nanometers. Carbon nano-material is one of the most popular materials in every field. Also carbon based hybrid magnetic materials have attract scientist’s widespread attention. Designing novel magnetic nano-materials with a reasonable way and also applying to the spin electronic devices has been an enduring subject of researchers.For the research of nano-materials, therehas emerged in a variety of methods, including experimental, theoretical and computational simulation.Calculations based on first-principles density functional theory have become an indispensable tool. In this paper, based on two-dimensional hybrid carbon material, we design the novel magnetic nanomaterials and study their electronic and magnetic properties using the method of first-principles calculations.In the first chapter, we introduce the main content of density functional theory. Firstly, we give a brief introduction aboutseveral approximations, including the Hartree-Fockapproximation,Thomas-Fermi-Diracapproximation. Then we introduce Kohn-Sham equation and the exchange-correlation energy functional. Finally, we describe several common computing software package based on density functional theory.In the second chapter, we first introduce the monolayer of graphite carbon nitride (g-C3N4), including the characteristic of structure, its properties and main applications. Then we use transition metals and non-metallic elements (B, C, N) to modify the structure of g-C3N4in order to get the novel magnetic nano-materials and to form the B-C-N ternary hybrid materials. Furthermore, we study the electronic and magnetic properties systematically using the first-principle calculation.In the third chapter, we introduce the magnetic properties of graphene with single vacancy controlled by the h-BN substrate. Firstly, we give a brief introduction about graphene and h-BN. As we know that h-BN substrate has some influence on the electronic properties of graphene. Then we design the magnetic graphene (graphene with single vacancy), and explore that how the h-BN substrate influences the magnetic properties of graphene with single vacancy (monolayer and bilayer graphene with single vacancy).