Based On The Lithium Ion Migration To Control The Magnetic Field Of Cobalt Oxide

Electric-field control of magnetization（magnetoelectric coupling）is the key to the development of high-density,low-power,high-speed,and multifunctional spintronic devices,and has become a hot research topic in the field of spintronics.In recent years,antiferromagnetics have attracted more and more researcher due to their advantages such as stable anti-interference and intrinsic high frequency.The manipulation of the electric-field control of magnetization of antiferromagnetic materials is the basis for the development of antiferromagnetic information technology information.Current voltage-driven magnetic regulation techniques include:the application of an electric field to accumulate/deplete carriers on the surface of the material for magnetoelectric regulation;the use of stress and strain between ferroelectric/ferromagnetic composite material interfaces;and magnetic-electric modulation using ferroelectricity and antiferromagnetic magnetoelectric coupling in multiferroic materials,etc.However,the electric-field control of magnetization is mostly limited to the limited thickness at the interface,and usually works at lower temperatures and higher voltages,and sometimes requires expensive single crystal ferroelectric substrates,so researchers have been exploring to achieve high efficiency with a new way of controlling the magnetic field of the electric field.Moreover,compared with the widely-developed research in ferromagnetic materials,there are still few explorations on the antiferromagnetic materials.In order to break through the interface limitation and realize the electric field manipulation of the antiferromagnetic material magnetism,we carried out the exploration and research on the electric field control of the antiferromagnetic material magnetism based on the structure of the lithium ion battery.Lithium ion battery（LIB）is a secondary battery that relies on lithium ion migration and energy storage.During the operation of the battery,lithium ions with the advantages of light weight and small radius will be quickly inserted/deintercalated in the electrode material.This process will be accompanied by the progress of the redox reaction,and the valence of some elements in the material will change.As a widely studied lithium ion negative electrode material,antiferromagnetic materials such as cobalt oxide and other transition metal oxides will change their magnetic properties as the charge and discharge progress,so magnetoelectric adjustment based on the mechanism of lithium ion batteries is worth looking forward to.Moreover,some studies have shown that the diffusion depth of lithium ions can reach several microns,and a large magnetic change value can be obtained.However,in the current field of magnetoelectric research,the research on the regulation of antiferromagnetic materials based on this mechanism still needs to be further developed.Based on the above analysis,we used the structure of the lithium-ion battery to study the magnetic change of the common antiferromagnetic material cobalt oxide during the migration of lithium ions.And in the Co/CoO,the exchange bias was changed by electric field.This way can break through the defects of traditional methods limited to the interface or surface.It is worth mentioning that this work also brings new characterization methods to the field of lithium ion batteries and promotes the research of the reaction mechanism of lithium ion batteries.In order to carry out lithium ion migration control magnetic work,we first mastered the assembly,test and analysis methods of lithium ion batteries through the study on the anode material MnSe₂ of lithium ion battery.Then,we selected the antiferromagnetic material CoO_x as the working electrode and lithium metal as the counter electrode.By changing the oxygen content in CoO_x,we systematically research on the magnetic change of the material under applied voltage and speculated the formation of SEI film requires the participation of cobalt element.Finally,in the Co/CoO double-layer film,the electric field control of the exchange bias field of the material is realized.Our work is helpful to develop a new way of electric field control magnetism and promote the development of new spintronic devices.