Study On Electromagnetic Characteristics And Regulation Mechanism Of Material Fe₂Ge

Fe₂Ge is a new type of electromagnetic material.Due to its high Curie temperature（theoretical value up to 400K）,high magnetization,low dielectric constant and excellent electromagnetic properties,Fe₂Ge has potential application value in electronic devices such as magnetic storage electron storage devices,magnetic storage electron transport devices and spintronics devices.However,there is still a certain distance between its electromagnetic properties and practical applications.In this paper,surface reconstruction,strain and doping methods are used to regulate its electronic structure and magnetic properties,in order to provide theoretical guidance for its experimental theoretical research and practical application.Its research content is mainly divided into the following three parts:1.Electronic structure and magnetism of Fe₂Ge bulkIn this part,the electronic structure and magnetic properties of Fe₂Ge bulk are calculated.By analyzing the band structure of Fe₂Ge,the up-spin band passes through Fermi level,and the down-spin band also passes through Fermi level,but the up-spin band and the down-0spin band separate,indicating that Fe₂Ge is a magnetic metal material.By analyzing the density of its electron states,it is found that the magnetic properties of Fe₂Ge are mainly derived from the d-state spintronic orbitals in Featoms,and the s and p states contribute little to the magnetic properties.Thus,the Fe₂Ge bulk is ferromagnetic.Through atom population analysis,the reason of magnetic formation is explained from two aspects:atomic magnetic moment and chemical bond magnetic moment.2.Electronic structure and magnetism of Fe₂Ge（001）surfaceThe electronic structure and magnetic properties of different terminal Fe₂Ge（001）surfaces are calculated.By analyzing their energy band structure and electron state density,it is found that Ge（I）-（001）terminal surface and Ge（II）-（001）terminal surface exhibit metallic characteristics and magnetic properties.The magnetic properties of Ge（I）-（001）terminal surface and Ge（II）-（001）terminal surface are mainly derived from the d-state spintronic orbitals in Featom,and the s and p states contribute little to their magnetic properties.The p state of Ge atom is affected by the spin of Fed state,showing a weak spin polarization.This indicates that there are hybridization and coupling of electrons in the Fed state and Ge p state in the surface system of Fe₂Ge.On this basis,by analyzing their spin polarizability,the spin polarizability of Ge（I）-（001）terminal surface is much higher than that of Ge（II）-（001）terminal surface,and the spin polarization degree of Fe₂Ge bulk is between that of the different terminal surfaces.By analyzing the atomic magnetic moment,the spin-polarized magnetism of Ge atom in Ge（II）-（001）terminal surface is stronger than that of Ge atom in Ge（I）-（001）terminal surface.This is due to the strong hybridization between the Fe-d and Ge-p state orbitals in the Ge（II）-（001）terminal surface.3.Electromagnetic regulation of coexistence of strain and dopingIn this part,the electronic structure and magnetic properties of Fe₂Ge surface system under different strains and Co doping are calculated.On the one hand,through the analysis of the calculated results,it is found that the system exhibits the same metal properties as the Fe₂Ge bulk and its（001）surface.In addition,it can also be found that the system has magnetism,and with the increase of strain,the magnetic size of the system presents a change law of first increasing,then decreasing,and then increasing.On the other hand,according to the changes of the electronic structure and magnetic properties of the doped Fe₂Ge surface system with the coexistence of doping and strain,the mechanism of the coexistence of strain and magnetic elements to regulate the electromagnetic properties of Fe₂Ge system is explained.