Modulation On Electronic Structure And Magnetic Properties Of Two-Dimensional SnO Monolayer

Two dimensional(2D)materials have attracted much attention due to its unique structure,high-speed carrier mobility and mechanical properties,etc.However,some intrinsic deficiencies of electronic structure and physical properties of 2D materials limit their practical applications in the electronic devices.Thus,it is necessary to find other 2D materials with desired physical properties.The 2D Tin monoxide(SnO)monolayer has been paid much attention due to its good oxidation resistance and bipolar conductivity,etc.Therefore,in this dissertation,the electronic structure and magnetic properties of two-dimensional SnO monolayer and its heterostructures are investigated by density functional theory.Firstly,the electronic structure of the fourth period transition metal(TM)atom adsorbed on SnO monolayer is calculated by density functional theory.Bader charge analysis shows that the n-type doping appears in the SnO monolayer when Sc,Ti,V,Cr,Mn,Fe and Zn are adsorbed.Co,Ni and Cu adsorptions induce the p-type doping.It is important that Fe,Co and Ni adsorbed SnO monolayers exhibit the perpendicular magnetic anisotropy(PMA),while Ti,V,Cr and Mn adsorbed SnO monolayers show the in-plane magnetic anisotropy(IMA).Secondly,the in-plane strain and interlayer distance effects on the electronic structure of 2D SnO/Cr N van der Waals heterostructures are calculated by density functional theory.At the tensile strains,Fermi level of monolayer SnO moves down and p-type doping appears.At the compressive strains,Fermi level of monolayer SnO moves upward and n-type doping appears.When the in-plane biaxial strain turns from compressive to tensile one,the PMA of Cr N monolayer in 2D SnO/Cr N van der Waals heterostructure increases,where the easy axis is perpendicular to the Cr N layer.Finally,the electronic structure and MAE of the SnO/Fe₄N heterostructures are investigated by density functional theory.The stacking patterns can affect the interfacial and inner PMA of Fe₄N,where the maximum value reaches 2.34 m J/m².At a tensile strain of 2%,the layer V of Fe₄N shows a transition from PMA to IMA.At a compressive strain of-4%and-6%,the layer IV,V and VII of Fe₄N turn from PMA to IMA.