Magnetic Properties Of Edge Hydrogenated Black Phosphorene Nanoribbon By Transition Metal Doping

With the advancement of information technology,people have high requirements on the integration degree and operation speed of integrated circuit in microelectronics industry.According to Moore's law,the performance of electronic devices made of semiconductor silicon is approaching the material limit,and the method of obtaining high performance chips by diminishing the size of transistors may not be maintained,so the performance of electronic devices cannot meet the development needs.People seek 2D materials with large development potential,the thickness of graphene is equal to a single atom,the thickness is 0.35 mm and weight is 0.77 mg/m~2,it has high hardness,good thermal conductivity and electrical conductivity.These excellent properties of graphene in flexible wearable electronic devices,batteries,especially spintronic materials get attention.But graphene can't apply in practical engineering because of the graphene without band gap,the area between the conduction band and valence band has no electron.Monolayer phosphene has a direct band gap of 1.5 eV and the band gap is adjustable,which is more suitable for the preparation of spintronic devices.However,two-dimensional materials are generally not magnetic,and the regulation of the magnetism of 2D materials is a significant research point in this field.The studies show that clipping nanoribons,edge modification,atomic doping,vacancy defects,stress and other means can regulate the magnetic properties of black phosphoene nanoribons.In this paper,the electronic structure and magnetism of transition metal doped hydrogenated zigzag black phosphorene nanoribbon(H-ZPNR)and the armchair black phosphorene nanoribbon(H-APNR)are studied.The work of this paper is divided into the following parts:(1)Firstly,H-ZPNR and H-APNR were modeled.The first-principles calculation results showed that the hydrogenated black phosphorene nanoribbon without magnetic properties.The general gradient approximation(GGA)method was used to calculate the effects of single transition metal Fe doping on the electronic structure and magnetic properties of H-ZPNR and H-APNR.Through the molecular dynamics simulation,it was found that the doping system was stable and showed magnetic moment about 1?B.In these doping system,Fe atom and the three adjacent P atoms are all anti-ferromagnetic coupled and localization.The magnetism mainly came from the d electron orbital of Fe atom and the p electron orbital of the adjacent P atoms.(2)Considering the strong electron correlation effect of d orbital electrons in Fe,Mn and V of 3d transition metal atom,GGA+U calculation method was adopted in the subsequent research.When a Fe atom doped H-ZPNR,the doping system shows magnetism and the magnetic moment is localized.The maximum total magnetic moment of the doping system under GGA+U method increases to 4.1?B,but Fe atom and adjacent P atoms have both ferromagnetic coupling and anti-ferromagnetic coupling.Furthermore,whether the doping of two Fe atoms would cause the expansion of the magnetized region,the influence of two Fe atoms on the P atom between them need further explored.In addition,the initial magnetic moment of two Fe atoms considered both ferromagnetic and anti-ferromagnetic states.(3)GGA+U was used to calculate the electronic structure,total electronic density of states,partial density of states and spin charge density and magnetism of the H-ZPNR with single Mn atom or V atom,two Mn atoms or V atoms.It was found that when a Mn atom central and marginal doped H-ZPNR,these doped systems have magnetic.The total magnetic moment of the two doped systems was about 3.86?B.A single V atom doped H-ZPNR have magnetic properties,while the marginal doped system has almost no magnetic.Two Mn atoms or two V atoms doped H-ZPNR have magnetic moment,and the magnetic moment is weak when the initial magnetic moment of transition metal is opposite,and the energy difference between the anti-ferromagnetic state and the ferromagnetic state of the doping system is pretty small,indicating that the two states maybe coexist.