Study On Magnetic Control And Mechanism Of ZnO Nanoribbons Under Electro Mechanical Coupling

In this paper,the magnetic mechanism under electric field,strains and coupling of strains and electricity of zigzag ZnO nanoribbons（Z₈-ZNNR）and N passived-armchair ZnO nanoribbons（N-A₈-ZNNR）were studied using the mean field approximation and the Coulomb correction（LDA+U）in DFT algorithm.By using electric field,strains and coupling of strains to changed the electronic structure of Z₈-ZNNR and N-A₈-ZNNR,so as to effectively modulate the magnetic properties of the system.Firstly,the electric field acting on Z₈-ZNNR and N-A₈-ZNNR are calculated and the magnetic properties are analyzed.The results are as follows:1.the magnetic moment of the zigzag ZnO nanoribbons（Z₈-ZNNR）and N-A₈-ZNNR can be effectively adjusted by the applied electric field.2.ZnO nanoribbons（ZNNR）have different response to different axial electric field.For Z₈-ZNNR,the magnetic moment of Z₈-ZNNR is mainly due to the contribution of O-2p orbital without electric field.Under the action of y-axis electric field,the Zn atoms and O atom of the o-terminal boundary are polarized,which makes more atoms participate in the spin polarization,leading to the change of magnetic moment of Z₈-ZNNR.Through the calculation of optical properties,it is found that the y-axis electric field can effectively adjust the absorption coefficient and reflection coefficient of Z₈-ZNNR in the visible region.The magnetic origin of N-A₈-ZNNR is generated by spin polarization between the O atoms and the N atoms at the end boundary of the O atoms.The main contribution of the magnetic moment is the N-2p orbit and the O-2p orbit.When the electric field is applied,the electric field will change the spin polarized charge density of O atoms and N atoms at the end boundary of O atom,and then change the magnetic moment of the system.Then the strains acting on the Z₈-ZNNR nanoribbons and N-A₈-ZNNR are calculated.Under uniaxial stress,the total magnetic moment of Z₈-ZNNR decreases under compression,and oscillates between decrease and increase under stretching.The properties of the system undergo the transition of the half metal-metal-half metal characteristics under the stress.The magnetism of the system comes from the contribution of O-2p orbital and Zn-3d orbital.The total magnetic moment of N-A₈-ZNNR increases under tensile action,but increases firstly and then decreases under compression.The characteristic of the system undergoes semiconductor-half metal-metal transition under stress.The magnetic properties of N-A₈-ZNNR come from the N-2p and O-2p orbital.Finally,Z₈-ZNNR and N-A₈-ZNNR under coupling of strains and electricity are calculated.The total magnetic moment of the Z₈-ZNNR decreases firstly and then increases under the action of 1V/nm electric field and normal stress.The characteristic of the system undergoes metal-semiconductor-half metal-semiconductor transition under coupling of strains and electricity.The magnetism of the system comes from Zn-3d and O-2p orbital.For N-A₈-ZNNR,the total magnetic moment decreases firstly and then increases under 3V/nm electric field and stress.The characteristic of the system undergoes metal-half metal transition.The magnetic properties of the system come from N-2p orbital,O-2p orbital and Zn-3d orbital.